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403 Cards in this Set
- Front
- Back
Absorb
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An object absorbs energy when the energy from infrared radiation is transferred to the particles of the object, increasing the temperature of the object
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Adaptation
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The way in which an organism evolved to become better able to survive in its environment
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Addiction
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When a person becomes dependent on a drug
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Addition reaction
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Reaction in which a C=C bond opens up and other atoms add on to each carbon atom
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Adrenaline
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Hormone that helps to prepare your body for action
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agar
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Substance used to make jelly on which bacteria can be grown. Made From Sea Weed.
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aggregate
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Stones, gravel or rock chippings used in the construction industry.
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alcohols
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A family of organic compounds containing an OH group, for example ethanol (In Beer, Cider Etc.)
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alkali metal
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Group 1 Metal in the periodic table, Lithium (Li), Sodium(Na) Potassium (K)Etc.
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alkanes
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Family of hydrocarbons: CnH(2n+2) with single covalent bonds, Example Source =crude oil
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alkenes
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Family of hydrocarbons: CnH2n with double covalent bonds (C=C), for example ethene (C2H4)
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alloy
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Mixture of two or metalic elements, with useful properties different from the individual metals, Eg Steel (Iron +Carbon) Solder (Lead+Tin)
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amino acids
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Small molecules from which proteins are built
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ampere (Amp, A)
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Unit used to measure electrical current,
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amplitude
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Size of wave oscillations - it describes how far the waves vibrate around their central position.
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angle of incidence
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Angle between the ray hitting a mirror 01 lens and the normal.
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angle of reflection
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Angle between a ray reflecting from a mirror and the normal.
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anode
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Positive electrode
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antibiotic
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Therapeutic drug acting to kill bacteria which is taken into the body
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antibiotic resistance
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Ability of bacteria to survive in the presence of an antibiotic
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antibody
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Protein normally present in the body or produced in response to an antigen which it neutralises, thus producing an immune response
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antiseptic
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Substance that kills pathogens
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antiviral
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Therapeutic drug acting to kill viruses appliance device that transfers the energy supplied by electricity into something useful
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aqueous solution
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Substances dissolved in water
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argon
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The most common noble gas - makes up nearly 1% of the air
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atmosphere
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Thin Layer of gas surrounding a planet atom the basic 'building block' of an element that cannot be chemically broken down
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atomic number
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Number of protons found in the nucleus of an atom
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attraction
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Force that pulls, or holds, objects together
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auxin
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A plant hormone that affects rate of growth
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axon
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Long thread of cytoplasm in a neurone, carrying an impulse away from the cell body
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bacteria
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Single-celled microorganisms that can either be free-living organisms or parasites (they sometimes invade the body and cause disease)
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balanced diet
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Eating foods (and drinking drinks) that will provide the body with the correct nutrients in the correct proportions
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balanced equation
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Chemical equation where the number of atoms of each element is the same in the reactants as in the products
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bauxite
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Main ore of aluminium - impure aluminium oxide (A1203)
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Big Bang theory
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Theory that states that the universe originated from a point at very high temperature, and everything in the universe formed as energy and matter exploded outwards tram that point and cooled down
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Biodegradable
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A biodegradable material can be broken down by microorganisms
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biodiesel
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Fuel made from plant oils such as rapeseed biodiversity range of different living organisms in a habitat
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biofuel fuel
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Such as wood, ethanol or biodiesel - obtained from living plants or animals
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biomass
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The mass of living material, including waste wood and other natural materials
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blast furnace
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Furnace f or extracting iron from iron ore blood plasma the liquid part of blood
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Bluetooth
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Low energy, short-range radio waves used to connect communications equipment such as mobile phones or laptops to other equipment nearby
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Boiling
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Change of state from liquid to gas that happens at the boiling point of a substance
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Brass
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Alloy of copper and zinc
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brittle
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Easily cracked or broken by hitting or bending bronze alloy of copper and tin
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Bromide
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Compound containing Bromine and another atom (Metal)
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brownfield site
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Former industrial site that may be redeveloped for other uses
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calcium carbonate
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Compound with chemical formula CaCO3 - main component of limestone
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carbon capture
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Technology that filters the carbon and carbon dioxide gas out of waste smoke and gases from power stations and industrial chimneys
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carbon cycle
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The way in which carbon atoms pass between living organisms and their environment
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carbon dioxide
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One of the gasses emitted from burning fossil fuels that contributes to global warming
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carbon sinks
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Carbon-containing substances, such as limestone and fossil fuels, which formed millions of years ago, removing carbon dioxide from the atmosphere
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carnivore
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An animal that eats other animals
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casting
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Making an object by pouring molten metal into a mould and allowing it to cool and solidify
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catalytic converter ('cat')
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The section of a vehicle's exhaust system that converts pollutant gases into harmless ones
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catalytic cracking
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Cracking hydrocarbons by heating in the presence of a catalyst
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cathode
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Negative electrode.
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cell body
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The part of a nerve cell that contains the nucleus.
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cement
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Substance made by heating limestone with clay, when mixed with water it sets hard like stone.
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central nervous system (CNS)
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Collectively the brain and spinal cord.
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chalcopyrite
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Common ore of copper - formula CuFeS2
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charge
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Particles or objects can be positively or negatively electrically charged, or neutral: similar charges repel each other, opposite charges attract.
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chemical bond
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Attractive force between atoms that holds them together (may be covalent or ionic)
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chemical equation
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Line of chemical formulae showing what reacts and what is produced during a chemical reaction.
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chemical reaction
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Process in which one or more substances are changed into other substances - chemical reactions involve rearranging atoms and energy changes
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Chloride
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Compound containing Chlorine and another atom (Metal)
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cholesterol
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Chemical needed for the formation of cell membranes, but that increases the risk of heart disease if there is too much in the blood
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chromosome
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Thread-like structure in the cell nucleus that carries genetic information
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climate change
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Changes in seasonal weather patterns that occur because the average temperature of Earth's surface is increasing owing to global warming
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clones
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Group of genetically identical organisms
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coal
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Solid fossil fuel formed from plant material -composed mainly of carbon. Sulpher is a common problamatic impurity.
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combustion
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Process where substances react with oxygen, releasing heat (Thermal energy)
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communications satellite
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Artificial satellite that stays above the same point on Earth's surface as it orbits, and used to send communications signals around the world
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community
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All the organisms, of all species, that live together in the same habitat at the same time.
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competition
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Result of more than one organism needing the same resource, which is in short supply
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compost
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Partly rotted organic material, used to improve soil for growing plants.
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compound
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Substance composed of two or more elements mat are chemically joined together, for example H20, H2SO4, CO2.
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compression
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Region of a longitudinal wave where the vibrating particles are squashed together more than usual
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concrete
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Mixture of cement, sand, aggregate and water
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condensation
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Change of state when a substance changes from a gas or vapour to a liquid: the substance condenses
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conduction (electrical)
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Transfer of energy when an electrical current passes through a material, A net movement or drift of electrons.
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conduction (thermal)
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Transfer of energy through a substance when it is heated
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conductor
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Material that transfers energy easily
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cone cell
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Receptor cell in the eye that detects colour of light (three types, R,G,B) See also rod cells.
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consumer
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An organism that feeds on other organisms
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continental drift
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Movement of continents relative to each other
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continental plate
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Tectonic plate carrying large landmass, though not necessarily a whole continent
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convection
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Heat transfer in a liquid or gas - when particles in a warmer region gain energy and move into cooler regions carrying this energy with them
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convection current
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When particles in a liquid or gas gain energy from a warmer region and move into a cooler region, being replaced by cooler liquid or gas
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coordination
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Communicating between different parts of the body so that they can act together
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core (of Earth)
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Layer in centre of Earth, consisting of a solid inner core and molten outer core
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cosmic microwave background radiation (CMBR)
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Microwave radiation coming very faintly from all directions in space
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covalent bond
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Bond between atoms in which some of the electrons are shared
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cracking
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Oil refinery process that breaks down large hydrocarbon molecules into smaller ones
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crust
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Surface layer of Earth made of tectonic plates
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culture
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A population of microorganisms, grown on a nutrient medium
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current (electric)
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Flow of electrons in an electric circuit
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cuttings
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Small pieces of a plant that can grow into complete new plants
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decay (biological)
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The breakdown of organ material by micro-organisms
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dendrite
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A short thread of cytoplasm on a neurone, carrying an impulse towards the cell body
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Dendron
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Long thread of cytoplasm on a neurone, carrying an impulse towards the cell body
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Diabetes
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Disease in which the body cannot control its blood sugar level. Type1or Type 2.
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Diffraction
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Change in the direction of a wave caused by passing through a narrow gap or round an obstacle such as a sharp corner. Also change of dirrection caused by a change of density ina medium.
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digital signaI
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Communications signal sent as an electromagnetic wave that is switched on and off very rapidly. (Binary signal)
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distillation
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Process for separating liquids by boiling them, then condensing the vapours. Also fractional distillation where mixed liquids are separated into fractions by temperature.
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distribution
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The transmission of electricity from a power station to homes and businesses
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DNA
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Polymer molecule found in the nucleus of all body cells - its sequence determines genetic characteristics, such as eye colour. Resembles a twisted ladder.
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Doppler effect
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Change in wavelength and frequency of a wave that an observer notices if the wave source is moving towards them or away from them. Used to explain RED SHIFT.
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double covalent bond
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Two covalent bonds between the same pair of atoms - each atom shares two of its own electrons plus two from the other atom
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drug
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A chemical that changes the chemical processes in the body
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drug dependency
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Feeling that you cannot manage without a drug
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earthquake
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Shaking and vibration at the surface of the Earth resulting from underground movement or from volcanic activity
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echo
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Reflection of a sound wave
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effector
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Part of the body that responds to a stimulus
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efficiency
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A measure of how effectively an appliance transfers the energy that flows into the appliance into useful effects
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egg
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Cell female gamete
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electrical power
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A measure of the amount of energy supplied each second
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electricity generator
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Device for generating electricity
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electrode
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Solid electrical conductors through which electrical current passes into and out of the liquid during electrolysis and at which the electrolysis reactions take place. Positive is Anode, Negative is Cathode.
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electrolysis
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Decomposing an ionic compound by passing an electric current through it while molten or in solution.
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electromagnetic (EM) radiation
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Energy transferred as electromagnetic waves.
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electromagnetic spectrum
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Electromagnetic waves ordered according to wavelength and frequency - ranging from radio waves to gamma rays.
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electromagnetic waves
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A group of waves that transfer energy - they can travel through a vacuum and travel at the speed of light.
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electron
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Small particle within an atom that orbits the nucleus (it has a negative charge)
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electronic configuration
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The arrangement of electrons in shells, or energy levels, in an atom.
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element
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Substance made out of only one type of atom.
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embryo
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A very young organism, which began as a zygote and will become a foetus (fetus).
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embryo transplant
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Taking an embryo that has been produced from one female's egg and placing it into another female.
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emit
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An object emits energy when energy is transferred away from the object as infrared radiation, decreasing the temperature of the object.
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emulsifier
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A substance that prevents an emulsion from separating back into oil and water.
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emulsion
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A thick, creamy liquid made by thoroughly mixing an oil with water (or an aqueous solution)
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energy
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The ability to 'do work'
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energy input
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The energy transferred to a device or appliance from elsewhere
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energy levels
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The arrangement of electrons in atoms (shells)
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energy output
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The energy transferred away from a device or appliance - it can be either useful or wasted
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energy transfers
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Occur when energy moves from one place to another, or when there is a change in the way in which it is observed
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environment
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An organisms surroundings
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enzyme
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Biological catalyst that increases the speed of a chemical reaction
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epidemic
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Many people having the same infectious disease
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essential oils
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Oils found in flowers, giving them their scent, they vaporise more easily than natural oils from seeds, nuts and fruit
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ethanol
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An alcohol that can be made from sugar and used as a fuel
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evaporation
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Change of state where a substance changes from liquid to gas at a temperature below its boiling point
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evolution
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A physical change in a species over multiple generations. A variation that produces surviving offspring thrive.
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extremophile
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An organism that can live in conditions where a particular factor, such as temperature or pH, is outside the range that most other organisms can tolerate
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fermentation
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Process in which yeast converts sugar into ethanol (alcohol) and CO2. Used to make food such as bread, beer, wine etc.
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fertilisation
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Fusion of the nuclei of a male and a female gamete develops into an embryo.
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fertility drug
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Hormone given to women to cause the ovaries to produce eggs.
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fibre optic cable
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Glass fibre that is used to transfer communications signals as light or infrared radiation.
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finite resource
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Material of which there is only a limited amount - once used it cannot be replaced
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flammable
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Catches fire and burns easily
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Fluoride
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Compound containing Fluorine and another atom (Metal)
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food chain
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Flow diagram showing how energy is passed from one organism to another
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formula (for a chemical compound)
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Group of chemical symbols and numbers, showing which elements, and how many atoms of each, a compound is made up of
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fossil fuel
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Fuel such as coal, oil or natural gas, formed millions of years ago from dead plants and animals
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fractional distillation
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Process that separates the hydrocarbons in crude oil according to size of molecules fractionating column tall tower in which fractional distillation is carried out at an oil refinery
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fractions
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The different substances collected during fractional distillation of crude oil
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freezing
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Change of state in which a substance changes from a liquid to a solid
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frequency
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The number of waves passing a set point per second
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FSH
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Hormone produced by the pituitary gland that causes eggs to mature in the ovaries
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fuel
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A substance that is burned for the purpose of generating heat
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fuel cell
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Device that generates electricity directly from a fuel, such as hydrogen, without burning it
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fungus (Pl. fungi)
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Living organisms whose cells have cell walls, but that cannot photosynthesise
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gamete
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Sex cell - a cell containing the haploid number of chromosomes, such as an egg or sperm
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gamma ray
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Ionising electromagnetic radiation - radioactive and dangerous to human health
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gasohol
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Mixture of gasoline (petrol) and alcohol (ethanol) used as a vehicle fuel
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gene
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Section of DNA that codes for a particular characteristic
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genetic engineering
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Changing the genes in an organism, for example by inserting genes from another organism
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genetically modified
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Organism that has had genes from a different organism inserted into it
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geothermal power station
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Power station generating electricity using the heat in underground rocks to heat water
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gland
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Organ that secretes a useful substance
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global dimming
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Gradual decrease in the average amount of sunlight reaching Earth's surface
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Global Positioning System (GPS)
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Navigation system using signals from communications satellites to find an exact position on the surface of Earth
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global warming
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Gradual increase in the average temperature of Earth's surface
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gravitropism
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A growth response to gravity
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green fuel
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Fuel that does less damage to the environment than fossil fuels
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greenhouse gas
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A gas such as carbon dioxide that reduces the amount of heat escaping from Earth into space, thereby contributing to global warming
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group
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Within the periodic table the vertical columns are called groups
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HDL
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A type of cholesterol that does not appear to cause heart disease and may help to protect against it
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heart disease
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Blockage of blood vessels that bring blood to the heart
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herbivore
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An animal that eats plants
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hormones
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Chemicals that act on target organs in the body (hormones are made by the body in special glands)
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hot spot
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Area of Earth's crust heated by rising currents of magma - Hawaii is above a mid-Pacific hot spot
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hydrocarbon
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Compound containing only carbon and hydrogen
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hydroelectric power station
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Power station generating electricity using the energy from water flowing downhill
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hydrophilic
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Water-loving (attracted to water, but not to oil) - used to describe parts of a molecule
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hydrophobic
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Water-fearing (attracted to oil, but not to water) - opposite of hydrophilic
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hydroxide
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Ion consisting of an oxygen and a hydrogen atom (written as OH-i)
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hypothesis
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An idea that explains a set of facts or observations - a basis for possible experiments
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image
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An image is formed by light rays from an object that travel through a lens or are reflected by a mirror
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immiscible
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Iiquids that do not mix, but form separate layers, are immiscible
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immune system
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A body system that acts as a defence against pathogens, such as viruses and bacteria
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immunity
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You have immunity if your immune system recognises a pathogen and fights it
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incident ray
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The ray of light hitting a mirror or lens
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infrared radiation
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Energy transferred as heat - a type of electromagnetic radiation
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inoculating loop
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Eetal loop that is used to transfer microorganisms
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insoluble
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Not soluble in water (forms a precipitate)
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insulator
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Material that transfers energy only very slowly - thermal insulators transfer heat slowly, electrical insulators do not allow an electric current to flow through them
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insulin
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Hormone made by the pancreas that reduces the level of glucose in the blood
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Iodide
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Compound containing Iodine and another atom (Metal)
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ion
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Atom (or groups of atoms) with a positive or negative charge, caused by losing or gaining electrons
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ionic bond
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Chemical bond between two ions of opposite charges
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ionise
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To cause electrons to split away from their atoms (some forms of EM radiation are harmful to living cells because they cause ionisation)
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IVF (in vitro fertilisation )
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The fertilisation of an egg by a sperm in a glass container
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joule
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Unit used to measure energy
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kilowatt-hour
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The energy transferred in 1 hour by an appliance with a power rating of 1 kW (sometimes called a 'unit' of electricity)
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kinetic theory
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Model used to explain how energy is transferred by particles in a substance
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laterally inverted
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Image left and right are reversed.
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laterally inverted image
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Left and right are reversed, when seen in a mirror
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lava
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Magma that has erupted onto the surface of Earth
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LDL
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A type of cholesterol that increases the risk of heart disease
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Leaching
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Using a chemical solution to dissolve a substance out of a rock
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LH
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Hormone produced by the pituitary gland, which causes an egg to be released from an ovary
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Lichen
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Small organism that consists of both a fungus and an alga
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Limestone
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Type of rock consisting mainly of calcium carbonate
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Limewater
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Calcium hydroxide solution
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Lithosphere
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The rocky, outer section of Earth, consisting of the crust and upper part of the mantle
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longitudinal wave
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A wave in which the direction that the particles are vibrating is the same as the direction in which the energy is being transferred by the wave
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low-grade ore
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Ore containing only a small percentage of metal
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lymphocyte
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Type of white blood cell
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magma
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Molten rock found below Earth's surface
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malnourished
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Not having a balanced diet
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mantle
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Semi-liquid layer of the Earth beneath the crust
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mass number
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Number of protons and neutrons in the nucleus of an atom
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mechanical wave
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Wave in which energy is transferred by particles or objects moving, such as a wave on a string or a water wave
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melting
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Change of state of a substance from liquid to solid
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menstrual cycle
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Monthly hormonal cycle that starts at puberty in human females
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menstruation
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Monthly breakdown of the lining of the uterus leading to bleeding from the vagina
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metabolic rate
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Rate at which chemical reactions take place in the body
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methane
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The simplest hydrocarbon, CH4 - main component of natural gas
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microorganism
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Very small organism (living thing) that can be viewed only through a microscope - also known as a microbe or microbeast KS3
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microwaves
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Non-ionising radiation - used in telecommunications and in microwave ovens
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mid-ocean ridge
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Underwater mountain range formed by magma escaping from the seabed where continental plates are drifting apart
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MMR
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Vaccine for measles, mumps and rubella
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molecular structure
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Arrangement of atoms from which a molecule is made
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Molecule
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Two or more atoms held together by covalent chemical bonds
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molten
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Made liquid by keeping the temperature above the substance's melting point
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monomers
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Small molecules that become chemically bonded to each other to form a polymer chain mortar mixture of cement, sand and water
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motor neurone
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Nerve cell carrying information central nervous system to muscles
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MRSA
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A form of the bacterium Staphylococcus aureus that is resistant to many antibiotics
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Mutation
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A change in the DNA in a cell
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myelin sheath
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Insulating layer around a nerve fibre
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National Grid
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Network that distributes electricity from power stations across the country
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"native (relating to metals such as gold)"
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Occurs in rocks as the element - not combined in compounds
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natural gas
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Gaseous fossil fuel formed from animals and plants that lived 100 million years ago - composed mainly of methane
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natural oil
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Oil produced by plants or fish natural selection process by which 'good' characteristics that can be passed on in genes become more common in a population
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nerve
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Group of nerve fibres neurone nerve cell
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neutral fuel
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Fuel grown from plants so that carbon dioxide is taken in as the plants are growing - this balances out the carbon dioxide released as the fuel is burned
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neutron
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Small particle that does not have a charge - found in the nucleus of an atom
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noble gas
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Unreactive gas in Group 0 of the periodic table
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non-renewable
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Something that cannot be replaced when it has been used, such as fossil fuels and metal ores
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normal
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Line at right angles to a boundary, such as the line drawn for mirrors or glass blocks to help draw ray diagrams
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nuclear power station
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Power station generating electricity from the energy stored inside atoms - energy is released by the controlled splitting apart of large atoms (nuclear fission)
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nucleus
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Central part of an atom that contains protons and neutrons
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nutrient
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Substance in food that we need to eat to stay healthy, such as protein
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nutrient medium
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Liquid or jelly in which microorganisms can be grown
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oceanic plate
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Tectonic plate under the ocean floor - it does not carry a continent
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oestrogen
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Female hormone secreted by the ovary and involved in the menstrual cycle
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OH
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Group an oxygen atom bonded to a hydrogen atom and found in all alcohols
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oil (crude)
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Liquid fossil fuel formed from animals and plants that lived 100 million years ago
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oil (from a plant)
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Liquid fat obtained from seeds, or fruit
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opencast mining
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Mining by digging out ore at the surface, rather than underground
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optical fibre or cable
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Glass fibre that is used to transfer communications signals as light or infrared radiation
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oral contraceptive
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Pills that prevent a woman releasing eggs
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ore
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Rock from which a metal is extracted, for example iron ore
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organic compound
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A compound containing carbon and hydrogen, and possibly oxygen, nitrogen or other elements - living organisms are made up of organic compounds
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oscillate
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Vibration to and fro of particles in a wave
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ovary
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Organ (in females) which makes eggs
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good characteristics
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Means that the organism has an advantage which makes it more likely to survive in the long term, years, centurys etc. over many generations..
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ovulation
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Release of an egg from the ovary
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oxidation
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Process that increases the amount of oxygen in a compound - opposite of reduction
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pandemic
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When a disease spreads rapidly across many countries - perhaps the whole world
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Pangaea
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Huge landmass with all the continents joined together before they broke up and drifted apart
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pathogen
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Harmful organism that invades the body and causes disease
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payback time
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Time taken for a type of domestic insulation to 'pay for itself' - to save as much in energy bills as it cost to install. Applies to micro-generation such as Photovoltaic solar panels (PV)
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period
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Horizontal row in the periodic table.
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periodic table
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A table of all the chemical elements based on their atomic number
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Petrochemical
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Substance made from petroleum
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Petroleum
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Liquid fossil fuel formed from animals and plants that lived 100 million years ago
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Phagocytes
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White blood cells that surround pathogens and digest them with enzymes
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photosynthesis
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Process carried out by green plants where sunlight, carbon dioxide and water are used to produce glucose and oxygen
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phototropism
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A growth response to light
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photovoltaic cell
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Device that converts the Sun's energy into electricity
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phytomining
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Using growing plants to absorb metal compounds from soil, burning the plants, and recovering metal from the ash
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phytoremediation
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Cleaning up contaminated soil by using growing plants to absorb harmful metal compounds
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placebo
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'Dummy' treatment given to some patients, in a drug trial, that does not contain the drug being tested
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plane mirror
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Mirror with a flat surface
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planet
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Large ball of gas or rock travelling around a star - for example Earth and other planets orbit our Sun
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plaque
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Build-up of cholesterol in a blood vessel (which may block it)
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plastics
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Compounds produced by polymerisation, capable of being moulded into various shapes or drawn into filaments and used as textile fibres
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plate boundaries
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Edges of tectonic plates, where they meet or are moving apart
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pollution
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Presence of substances that contaminate or damage the environment
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poly(ethene)
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Plastic polymer made from ethene gas (also called polythene)
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polymer
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Large molecule made up of a chains of monomers
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polymerisation
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Chemical process that combines monomers to form a polymer: this is how polythene is formed
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Power
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Amount of energy that something transfers each second and measured in watts (or joules per second)
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power rating
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A measure of how fast an electrical appliance transfers energy supplied as an electrical current
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power station
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Place where electricity is generated to feed into the National Grid
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producer
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Organism that makes its own food from inorganic substances
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products
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Chemicals produced at the end of a chemical reaction
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progesterone
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Hormone produced by the ovary that prepares the uterus for pregnancy
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protein
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Molecule made up of amino acids (found in food of animal origin and also in plants)
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proton
|
Small positive particle found in the nucleus of an atom
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pyramid of biomass
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A diagram in which boxes, drawn to scale, represent the biomass at each step in a food chain
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quarry
|
Place where stone is dug out of the ground
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radio wave
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Non-ionising radiation used to transmit radio and TV
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rarefaction
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Areas of a longitudinal wave in which the vibrating particles are spread out more than usual
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rate of energy transfer
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A measure of how quickly something moves energy from one place to another
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ray diagram
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Diagrams showing how light rays travel
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reactants
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Chemicals that are reacting together in a chemical reaction
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receptor
|
Nerve cell that detects a stimulus red shift when lines in a spectrum are redder than
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red shift
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When lines in a spectrum are redder than expected - if an object has a red-shift it is moving away from the observer
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reduction
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Process that reduces the amount of oxygen in a compound, or removes all the oxygen from it - opposite of oxidation
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reflected ray
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Ray of light 'bouncing off' from a mirror or reflecting surface
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reflection
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Change of direction of a wave when it 'bounces off' from a surface
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reflex action
|
A fast, automatic response to a stimulus reflex arc pathway taken by nerve impulse from receptor. through nervous system, to effector
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refraction
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Change of direction when a wave hits the boundary between two media at an angle, for example when a light ray passes from air into a glass block
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renewable resource
|
Energy resource that is constantly available or can be replaced as it is used
|
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repeatability
|
Consistent results are obtained when a person uses the same procedure a number of times
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reproducibility
|
Consistent results are obtained when a number of people use the same procedure
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resistant strain (of bacteria)
|
A population of bacteria that is not killed by an antibiotic
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respiration
|
Process occurring in living things in which oxygen is used to release the energy in foods
|
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rod cell
|
Receptor cell in the eye that detects light intensity. See also Cone Cell.
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rutile
|
An ore of titanium - impure titanium oxide (1102)
|
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Sankey diagram
|
Diagram showing how the energy supplied to something is transferred into 'useful' or 'wasted' energy
|
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saturated fat
|
Mostly, ' solid' fat, most often of animal origin, containing no C=C double bonds
|
|
saturated hydrocarbon
|
Hydrocarbon containing only single covalent bonds
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secretion
|
Production and release of a useful substance
|
|
sensory neurone
|
Nerve cell carrying information from receptors to the central nervous system
|
|
shape memory alloy
|
Alloy that 'remembers' its original shape and returns to it when heated
|
|
shells
|
Electrons are arranged in shells (or orbits) around the nucleus of an atom
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slag
|
Waste material produced during smelting of a metal- it contains unwanted impurities from the ore
|
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smelting
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Extracting metal from an ore by reduction with carbon - heating the ore and carbon in a furnace
|
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solar cell
|
Device that converts the Sun's energy into electricity
|
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solar panel
|
Panel that uses the Sun's energy to heat water
|
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solar power
|
Station power station generating electricity using energy transferred by the Sun's radiation
|
|
solar power station
|
Power station generating electricity using energy transferred by the Sun's radiation
|
|
solvent
|
Liquid in which solutes dissolve to form a solution
|
|
specific heat capacity
|
A measure of the amount of energy needed to raise the temperature of 1 kg of a substance by 1 °C
|
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speed of light
|
Speed at which electromagnetic radiation travels through a vacuum -approx 300 000 000 metres per second
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sperm
|
Male sex cell of an animal
|
|
stainless steel
|
Steel alloy containing chromium and nickel to resist corrosion
|
|
state symbol
|
Symbol used in equations to show whether something is solid, liquid, gas or in solution in water
|
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states of matter
|
Substances can exist in three states of matter (solid, liquid or gas) - changes from one state to another are called changes of state
|
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statin
|
Drug that reduces cholesterol level in the blood
|
|
steam cracking
|
Cracking hydrocarbons by mixing with steam and heating
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|
steam distillation
|
Process of blowing steam through a mixture to vaporise volatile substances - used to extract essential oils from flowers
|
|
steel
|
Alloy of iron and carbon ther metals added depending on its intended use
|
|
step-down transformer
|
Transformer that changes alternating current to a lower voltage
|
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step-up transformer
|
Transformer that changes alternating current to a higher voltage
|
|
sterile
|
Containing no living organisms
|
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sterile technique
|
Handling apparatus and material to prevent microorganisms from entering them
|
|
stimulus
|
A change in the environment that is detected by a receptor
|
|
sub-atomic particle
|
Particle that make up an atom -proton, neutron, electron
|
|
subduction zone
|
Area of ocean floor in which an oceanic plate is sinking beneath a continental plate
|
|
sugar
|
Sweet-tasting compound of carbon, hydrogen and oxygen such as glucose or sucrose
|
|
sulfur dioxide
|
Poisonous, acidic gas formed when sulfur or a sulfur compound is burned
|
|
sulphur dioxide
|
Poisonous, acidic gas formed when sulphur or a sulphur compound is burned
|
|
surface area
|
A measure of the area of an object that is in direct contact with its surroundings
|
|
sweat
|
Liquid secreted onto the surface skin that has a cooling effect as it evaporates
|
|
symbol (for an element)
|
One or two letters used to represent a chemical element, for example C for carbon or Na for sodium
|
|
synapse
|
Gap between two neurones
|
|
synthetic
|
Made by people
|
|
target organ
|
The part of the body affected by a hormone
|
|
tectonic plate
|
Section of Earths crust that floats on the mantle and slowly moves across the surface
|
|
telecommunications
|
Communications over long distances using various types of electromagnetic radiation
|
|
thalidomide
|
A drug that was originally prescribed to pregnant women but was found to cause deformities in foetuses (foetuses)
|
|
thermal decomposition
|
Chemical reaction in which a substance is broken down into simpler chemicals by heating it
|
|
tidal power station
|
Power station generating electricity using the energy transferred by moving tides
|
|
tissue
|
Group of cells that work together and carry out a similar task, such as lung tissue
|
|
toxin
|
Poisonous substance (pathogens make toxins that make us feel ill)
|
|
transfer (energy)
|
Energy transfers occur when energy moves from one place to another, or when there is a change in the way in which it is observed
|
|
transformer
|
Device by which alternating current of one voltage is changed to another voltage
|
|
transition metals
|
Group of metal elements in the middle block of the periodic table - includes many common metals
|
|
transmitter chemical
|
Chemical that transfers a nerve impulse across a synapse
|
|
transverse wave
|
A wave in which the vibration of particles is at right angles to the direction in which the wave transfers energy
|
|
tropism
|
Response of a plant to a stimulus, by growing towards or away from it
|
|
tsunami
|
Huge waves caused by earthquakes - can be very destructive
|
|
turbine
|
Device for generating electricity - the turbine has coils of wire that rotate in a magnetic field to generate electricity
|
|
ultraviolet radiation
|
Electromagnetic radiation can damage human skin
|
|
unsaturated fats
|
Liquid fats, containing C=C double bonds - usually from plants or fish
|
|
unsaturated hydrocarbon
|
Hydrocarbon containing one or more C=C double bonds
|
|
upright image
|
Image that the object is the correct way up.
|
|
U-value
|
A measure of how easily energy is transferred through a material as heat
|
|
vaccine
|
Killed microorganisms, or damaged, living but weakened microorganisms, that are given to produce immunity to a particular disease
|
|
vacuum
|
A space in which there are no particles of any kind
|
|
vaporise
|
Change from liquid to gas (vapour) . Boil or Evaporation of a liquid.
|
|
vent
|
Crack or weak spot in the Earths crust, through which magma reaches the surface. Also split in a jacket or other hole into an object.
|
|
virtual image
|
Image that can be seen but cannot be projected onto a screen (a mirror forms a virtual image behind the mirror)
|
|
virus
|
Very small infectious organism that reproduces within the cells of living organisms and often causes disease
|
|
volcano
|
Landform (often a mountain) where molten rock erupts onto the surface of the planet
|
|
voltage
|
A measure of the energy carried by an electric current (the old name for potential difference)
|
|
vulva
|
Female external sexual organs.
|
|
wasted energy
|
Energy that is transferred by a device or appliance in ways that are not wanted, or useful
|
|
watt
|
Unit of energy transfer - one watt is a rate of energy transfer of one joule per second
|
|
wave equation
|
The speed of a wave is always equal to its frequency multiplied by its wavelength
|
|
wave power
|
Electricity generation using the energy transferred by water waves as the water surface moves up and down
|
|
wavelength
|
Distance between two wave peaks
|
|
wind turbine
|
Device generating electricity by using the energy in moving air to turn a turbine and a generator
|
|
X-rays
|
Ionising electromagnetic radiation - used in X-ray photography to generate pictures of bones
|
|
yeast
|
Single-celled fungus used in making bread and beer
|
|
zygote
|
A diploid cell formed by the fusion of the nuclei of two gametes
|
|
variation
|
Differences between individuals belonging to the same species
|
|
cast iron
|
Iron containing 3-4% carbon - used to make objects by casting. Very hard and Brittle
|
|
Antitoxin
|
antitoxin substance produced by white blood cells that neutralises the effects of toxins
|