| properties of solids | fixed pattern, only vibrate, close together, strong attractive forces |
| properties of liquids | no fixed pattern, slide past each other, close together, weak forces |
| properties of gasses | random movement, move everywhere rapidly, far apart, |
| what happens as a solid gets heated | particles gain energy and vibrate more, the forces of attraction between particles are weakened as the solid melts, |
| heating and cooling curve | heating and cooling curve |
| diffusion in terms of kinetic particle theory | random movement of particles from an area of high concentration to an area of low concentration |
| effect of relative molecular mass on the rate of diffusion of gasses | molecules that have a lower mass move faster, if light and heavy molecules have the same amount of energy when they collide the lighter ones will bounce off the heavier ones quicker, so lighter molecules will diffuse faster than heavier molecules |
| atom | the smallest particle of a chemical element that can exist, singular |
| molecule | a group of atoms bonded together |
| element | A chemical element is a chemical substance that cannot be broken down into other substances, made up of one type of atom |
| compound | substance made up of two or more different types of atoms chemically bonded |
| mixture | two or more elements or compounds that are not chemically bonded |
| structure of the atom | central nucleus containing neutrons and protons surrounded by electrons in shells |
| Relative mass and charge of protons | 1, +1 |
| Relative mass and charge of neutrons | 1, no charge |
| Relative mass and charge of electrons | 0.00054, -1 |
| how to find number of protons/electrons | atomic number |
| how to find number of neutrons | atomic mass - number of protons |
| number of outer shell electrons | group number (downwards) |
| number of occupied electron shells | period number (across) |
| isotopes | different atoms of the same element that have the same number of protons but different numbers of neutrons |
| effect of isotopes on properties of the element | have the same chemical properties because they have the same number of electrons and therefore the same electronic configuration, but differ in mass and therefore in physical properties |
| ionic bond | attraction between positive ions and negative ions |
| properties of ionic compounds | high melting and boiling points, good electrical conductivity when aqueous or molten but poor when solid, soluble |
| Giant ionic structures form between | metal and non-metal |
| Giant ionic structures examples | Sodium chloride |
| Simple molecule structure forms between | non-metals |
| properties of simple molecular compounds | low melting and boiling points because of weak intermolecular forces, poor electrical conductivity |
| Simple molecule structure examples | oxygen |
| how is a covalent bond formed | when a pair of electrons is shared between two atoms, leading to noble gas electronic configurations |
| covalent bond properties | low melting points and boiling points, do not conduct electricity, insoluable |
| Giant covalent structures form between | non-metals |
| structure of graphite | structure of graphite |
| use of graphite | lubricant as an electrode |
| structure of diamond | structure of diamond |
| use of diamond | cutting tools |
| metallic bonding | electrostatic attraction between the positive ions in a giant metallic lattice and a sea of delocalised electrons |
| metallic bonding properties | good electrical conductivity, malleable, ductile |
| molecular formula of a compound | the number and type of different atoms in one molecule |
| relative atomic mass | the average mass of the isotopes of an element compared to 1/12th of the mass of an atom of 12C |
| relative molecular mass | as the sum of the relative atomic masses relative formula mass, Mr, will be used for ionic compounds |
| empirical formula of a compound definition | the simplest whole number ratio of the different atoms or ions in a compound |
| acid | proton donors |
| strong acid | an acid that is completely dissociated in aqueous solution |
| weak acid | an acid that is partially dissociated in aqueous solution |
| acid + metal | salt + hydrogen |
| acid + metal oxide | salt + water |
| acid + metal hydroxide | salt + water |
| acid + metal carbonate | salt + water + carbon dioxide |
| acid + ammonia | ammonia salt |
| acid's effect on methyl orange | turns red immediately |
| acid + base | salt + water |
| bases | oxides or hydroxides of metals, proton acceptors |
| alkalis | soluable bases |
| bases + ammonium salts | metal salt + ammonia + water |
| alkalis effect on methyl orange | turns yellow |
| aqueous solutions of acids | H+ ions |
| aqueous solutions of alkalis | OH- ions |
| neutralization reaction (symbols) | H+ (aq) + OH- (aq) --> H2O (l) |
| how are basic oxides formed | by the direct combination of a metal with an oxygen, most metal oxides are basic oxides |
| basic oxide reactions | react with acids to form a salt and water, do not react with alkalis, most don't react with water (except group 1 and group 2 which react to form a metal hydroxide) |
| how are acidic oxides formed | direct reaction with oxygen, most non-metal oxides |
| acidic oxide reactions | react with alkalis to form a salt and water, react with water to form acidic solutions |
| amphoteric oxides | oxides that react with acids and with bases to produce a salt and water |
| 1cm to dm3 | (÷ 1000) = 0.001 |
| identifying oxygen | put a glowing splint into the test tube and if the gas is oxygen the splint will re light |
| rule for solubility | nitrates, sodium potassium and ammonium salts, sulfates EXCEPT barium calcium and lead, chlorides EXCEPT lead and silver |
| rules for insolubility | carbonates EXCEPT sodium potassium and ammonium, hydroxides EXCEPT sodium potassium ammonium and partially calcium |
| hydrated substance | chemically combined with water |
| anhydrous substance | containing no water |
| periodic table definition | an arrangement of elements in periods and groups and in order of increasing proton/atomic number |
| how can the position of an element predict its properties | each element in the group has the same number of electrons in its outer shell |
| trends in groups | group I elements get more reactive as they go down, group VII get less reactive down the group, in many groups there is a trend less metallic at the top and more metallic at the bottom |
| group I metals trends | relatively soft metals but getting softer going down, melting and boiling points decrease, increase in density, increasing reactivity |
| group VII (halogens) trends | increasing density, decreasing reactivity, melting and boiling points increase, colour gets darker, state of halogens at room temp goes from gas to liquid to solid |
| appearance of chlorine at r.t.p | pale yellow-green gas |
| appearance of bromine at r.t.p | red-brown liquid |
| appearance of iodine at r.t.p | grey-black solid |
| transition elements | have high densities, high melting points, form coloured compounds, often act as catalysts as elements and in compounds, have ions with variable oxidation number e.g. iron (ii) & iron (iii) |
| group VIII noble gases trends | all unreactive, increased boiling points, increasing density |
| solvent | a substance that dissolves a solute |
| solute | substance that is dissolved in a solvent |
| solution | mixture of one or more solutes dissolved in a solvent |
| saturated solution | solution containing the maximum concentration of a solute dissolved in the solvent at a specified temp |
| residue | substance that remains after evaporation, distillation, filtration or any similar process |
| filtrate | liquid or solution that has passed through a filter |
| concentration equation | concentration = number of moles/volume of solution in dm3 |
| when is precipitation method used | if the salt you trying to make is insoluable |
| when to use titration method | bases and the salt is soluable |
| when to use insoluble base method | when the base in insoluble |
| test for ammonia | turns damn red litmus paper blue |
| test for carbon dioxide | turns limewater milky |
| test for chlorine | bleaches damp litmus paper |
| flame test for lithium | red |
| flame test for sodium | yellow |
| flame test for potassium | lilac |
| flame test for calcium | orange - red |
| flame test for barium | light green |
| flame test for copper | blue-green |
| mole | unit of amount of substance that one mole contains |
