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78 Cards in this Set
- Front
- Back
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What are atoms |
Smallest parts of any element |
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What is an element ? |
A substance that only contains one sort of atom |
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What is a compound ? |
An substance that contains two or more element which are chemically fixed in proportions |
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What are mixtures ? |
Mixtures consist of two or more elements or compounds which are not chemically combined |
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What are the 5 ways to separate a mixture ? |
Filtration Crystallisation Simple distillation Fractional distillation Chromatography |
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What is filtration ? |
When you filter a mixture with a separate soluble solid from an liquid |
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What is crystallisation ? |
When you warm a liquid and the water evaporates leaving just the crystals behind |
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What is distillation ? |
Heating up a liquid so it becomes gas then condensing it into another beaker - all dissolved solids will be left and fresh water will be in new beaker |
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What is fractional distillation? |
When you separate mixtures using there different boiling points - crude oil |
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What is chromatography ? |
Separating dyes or ink by the ink travelling up the paper |
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Timeline of the atom |
Early model atoms where just spheres 1898 Thomson discovered electrons also thought there was a random sea of positive charge around -plum pudding mode Geiger and marsden did gold sheet test with alpha particles where some were reflected Rutherford used results to conclude that the positive had to be in a small concentrated area -named nucleus Bohr deduced that electrons had to orbit at specific distances otherwise they would spiral inwards |
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What are the relative mass and relative charge for proton neutron and elactron |
Particle. Mass. Charge. Proton. 1. 1 Neutron. 1. 0 Electron. V smol. -1 |
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What link protons and electrons |
All atoms have an equal number of protons and electrons |
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What is the atomic number ? |
The number of protons in an atom and lies below |
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What is the mass number ? |
The number of protons and neutrons added together - top number on element |
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What are isotopes |
Isotopes are the same element with the same number of protons but different number of neutrons |
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What are ions ? |
When atoms gain or lose electrons they become an ion Metal atoms lose electrons to become positive ions Non metal atoms gain electrons to become negative ions |
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What are the relative mass and relative charge for proton neutron and elactron |
Particle. Mass. Charge. Proton. 1. 1 Neutron. 1. 0 Electron. V smol. -1 |
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What link protons and electrons |
All atoms have an equal number of protons and electrons |
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What is the atomic number ? |
The number of protons in an atom and lies below |
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What is the mass number ? |
The number of protons and neutrons added together - top number on element |
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What are isotopes |
Isotopes are the same element with the same number of protons but different number of neutrons |
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What are ions ? |
When atoms gain or lose electrons they become an ion Metal atoms lose electrons to become positive ions Non metal atoms gain electrons to become negative ions |
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History of periodic table |
Made in 1864 with only 63 element by John new lands Dimitri Mendeleev realised some elements still need to be found and created his table in 1869 and left gaps Gaps now filled |
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What are the relative mass and relative charge for proton neutron and elactron |
Particle. Mass. Charge. Proton. 1. 1 Neutron. 1. 0 Electron. V smol. -1 |
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What link protons and electrons |
All atoms have an equal number of protons and electrons |
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What is the atomic number ? |
The number of protons in an atom and lies below |
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What is the mass number ? |
The number of protons and neutrons added together - top number on element |
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What are isotopes |
Isotopes are the same element with the same number of protons but different number of neutrons |
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What are ions ? |
When atoms gain or lose electrons they become an ion Metal atoms lose electrons to become positive ions Non metal atoms gain electrons to become negative ions |
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History of periodic table |
Made in 1864 with only 63 element by John new lands Dimitri Mendeleev realised some elements still need to be found and created his table in 1869 and left gaps Gaps now filled |
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What are group 0 |
Group 0 are noble gases They have a full outer shell of electrons This means they are very stable and not reactive |
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What are group 1 |
Group 1 are alkali metals One electron in outer shell Low melting and boiling pints Low density so float When mixed with a non metal they form an ionic compound React with oxygen and water so are stored under oil When they react with water they produce a hydroxide and hydrogen gas |
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What are group 7 |
They are halogens and have 7 electrons in outer shell React with metals to make ionic salts A more reactive halogen will displace a less reactive halogen from an aqueous solution of its salt |
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Three types of chemical bonds |
Ionic Covalent Metallic |
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What is ionic bonding |
When a metal atom loses electrons to become positively charged and non metal atoms gain electrons to become negatively charged to from bond Strong electrostatic force of attraction |
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Properties of ionic compounds |
Giant structures of ions High melting and boiling points Do not conduct electricity when solid because ions can’t move or molten |
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What is a covalent bond |
Covalent bond is a shared pair of electrons between atoms Used to gain a full outer shell of electrons Occur in non metallic elements e.g oxygen Compounds of non metals |
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What are “small molecules “ |
A small number of non metal atoms joined together by covalent bonds Can’t conduct electricity Usually have low melting points and boiling points Have weak intermolecular forces holding them together |
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What are “small molecules “ |
A small number of non metal atoms joined together by covalent bonds Can’t conduct electricity Usually have low melting points and boiling points Have weak intermolecular forces holding them together |
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Properties of diamond |
Diamond is a giant covalent structure Made of carbon atoms which have 4 strong covalent bonds with other carbon atoms Has high melting and boiling point Doesn’t conduct electricity |
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Properties of graphite |
Giant covalent structure which is layered in an hexagonal way Each carbon atom forms 3 covalent bonds with other carbon atoms Layers are connected by weak intermolecular forces so layers can slide past each other among graphite soft and slippery Has one delocalised electron so can conduct heat and electricity |
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Properties of diamond |
Diamond is a giant covalent structure - lattice structure Made of carbon atoms which have 4 strong covalent bonds with other carbon atoms Has high melting and boiling point Doesn’t conduct electricity |
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Properties of silicone dioxide |
Same lattice structure as a diamond Each oxygen atom is joined to two silicon atoms Each silicon atom is joined to four oxygen atoms |
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What is graphene |
A single layer of graphite Arranged in hexagonal structure just one atom thick Very strong a good thermal and electrical conductor and nearly transparent |
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What are fullerenes |
Fullerenes are hollow shapes which are made up of a different number of carbon atoms Used for : Delivering drugs into the body Lubricants Catalysts Reinforcing materials - sting lightweight tennis rackets |
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What are polymers |
Large molecules made of strong covalent bonds between carbon and hydrogen Intermolecular forces are strong Solid at room temperature |
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What are polymers |
Large molecules made of strong covalent bonds between carbon and hydrogen Intermolecular forces are strong Solid at room temperature |
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What are plastics ? |
Man made polymers (synthetic ) |
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Properties of metallic bonding |
A metallic bond is the attraction of positive ions and delocalised negative electrons Happens between two matallic elements Happens in alloys e.g stainless steel Lattice structure with delocalised electrons in outer shell |
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Properties of metals |
High melting and boiling points Very strong Conduct heat and electricity Pure metals are easy to shape and bend due to regular layers |
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Properties of metals |
High melting and boiling points Very strong Conduct heat and electricity Pure metals are easy to shape and bend due to regular layers |
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What are alloys ? |
Alloys are metals that have another element added to them This creates an disturbed arrangement of metal atoms in layers and meaning they aren’t as soft Meanest alloys are stronger and harder than pure metals |
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What is an exothermic reaction |
Heat going into the surroundings |
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What is an exothermic reaction |
Heat going into the surroundings |
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What is an endothermic reaction |
A reaction where heat goes into the chemicals |
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What is activation energy |
The minimum amount of energy that the particles must have for a reaction to takes place Catalysts reduce the activation energy needed |
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How to determine whether a reaction is endothermic or exothermic |
Every chemical reaction bonds are broken and remade Breaking chemical bonds is endothermic Forming a new bond is exothermic If more energy is required to break bonds than is released when bonds are formed -its an exothermic reaction |
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What is the conservation of mass |
That the total mass of the products is equal to the total mass of the reactants |
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How can the mass change |
If gases are lost -not a closed system If something reacts with air making the weight increase |
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Value of 1 mole |
6.02 x10(23) known as Avogadro constant |
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Value of 1 mole |
6.02 x10(23) known as Avogadro constant |
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Equation for moles |
Mass of substance/ atomic mass Mr mole lives under the mass |
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What is the limiting reactant |
The reactant that is used up during the reaction and stops the reaction going any further |
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What is oxidation and reduction |
Oxidation is when a substance gains oxygen Reduction when a substance loses oxygen |
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Order of reactivity series |
Potassium Sodium Calcium Magnesium Aluminium Carbon Zinc Iron Tin Lead Hydrogen Copper Silver Gold Platinum |
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What is a displacement reaction |
When a more reactive metal will replace a less reactive metal from a solution of its salt |
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How to exstract metals |
Metal oxides that are less reactive than carbon can be reacted with carbon to make the metal and carbon dioxide |
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Ph scale - what’s alkaline what’s acidic |
Neutral is 7 Acidic is less than 7 Alkaline is more than 7 |
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What happens when an alkaline reacts with an acid |
Acids contain hydrogen ions H+ Alkalis contain hydroxide OH- When react the ions interacts making water |
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What salts do hydrochloric ,nitric and sulphuric acid make ? |
Hydrochloric acid - chloride salts Nitric acid - nitrate salts Sulphuric acid - sulphate salts |
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Strong acids are ...... in water |
Strong acids are completely ionised in water |
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What are electrolyte ? |
The substance being broken down in electrolysis |
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What are the electrodes |
Solids that conduct electricity Anode- positive electrode - negatively charged ions are attracted to it Cathode -negative electrode - positively charged ions are attracted to it |
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What happens at the cathode |
Positively charged ions gain electrons to form pure metal |
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What happens at the cathode |
Reduction Positively charged ions gain electrons to form pure metal |
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What happens at the anode |
Oxidation Negatively charged ions move to anode and lose electrons |
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What happens in electrolysis in aqueous solution |
Negative electrode : hydrogen is produced if the metal is more reactive than hydrogen - Metal is produced if not Positive electrode : oxygen is produced unless solution contains halide ions - if halide ions are present then the halogen is produced |
