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403 Cards in this Set

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