Year 10 IGCSE Key Terms – Flashcards
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| acid |
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| any substance that produces hydrogen ions, H+, when dissolved in water |
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| acid rain |
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| rain with a pH less than 5.6; acid rain has been made more acidic than normal rain because sulfur oxides and nitrogen oxides have dissolved in it; acid rain causes damage to buildings made from limestone, damages metal structures, kills fish, damages leaves in trees so they photosynthesise less |
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| activation energy |
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| minimum amount of energy needed to start the reaction/for a successful collision. |
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| actual yield |
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| the amount of product obtained when carrying out a reaction |
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| addition reaction |
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| a reaction in which atoms are added to an unsaturated carbon compound; the atoms are added using the double bond as one of the double bonds breaks and is used to make two new bonds, e.g. alkenes and halogens |
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| addition polymer |
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| polymer formed by addition polymerization; adding many unsaturated monomers using double bonds |
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| alcohol |
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| a homologous series of organic compounds which has -OH as its functional group; ethanol is a member of this homologous series |
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| alkanes |
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| a homologous series of hydrocarbons which are saturated as they have only single bonds between the carbon atoms |
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| alkenes |
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| a homologous series of hydrocarbons which are unsaturated as they have at least 1 double bond somewhere in the chain |
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| alloys |
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| mixture of a metal and small amounts of other metals and non-metals, made to have certain improved properties eg harder, stronger, increased resistance to corrosion, increased heat or electrical resistance |
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| alkali |
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| any base which is soluble in water |
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| anions |
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| negative ions; attracted to anode |
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| anode |
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| positive electrode in electrolysis |
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| atomic number |
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| number of protons in the nucleus of an atom, determines the order and place of each element in the Periodic Table |
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| base |
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| a substance which can neutralise an acid to make a salt and water examples: metal oxides, metal hydroxides, |
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| catalyst |
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| a substance which speeds up a reaction but which remains unchanged at the end of the reaction |
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| catalytic converter |
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| a piece of equipment which is part of the exhaust of a car and which changes nitrogen oxides into nitrogen before they are released into the atmosphere |
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| cathode |
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| negative electrode in electrolysis |
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| cation |
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| positive ion ; attracted to cathode |
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| combustion |
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| burning, the reacting of a substance with oxygen, exothermic |
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| complete combustion |
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| combustion in sufficient oxygen which in the case of hydrocarbons produces carbon dioxide and water |
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| compound |
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| a pure substance made from two or more different atoms joined together chemically |
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| condensation |
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| a process during which a gas changes into a liquid because its particles are having less energy, slow down and come much closer together |
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| covalent bond |
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| force of attraction between a pair of shared electrons and the nucleii of both atoms |
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| cracking |
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| the breaking down of long-chain alkanes into smaller alkanes and alkenes using a catalyst and heat (500 C) |
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| displacement reaction |
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| a reaction in which a more reactive metal or halogen takes the place of a less reactive metal or halogen in its compound |
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| ductile |
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| can easily be drawn into wires, what metals are |
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| electrolysis |
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| a reaction which uses electricity to decompose a compound |
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| electrolyte |
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| an ionic compound or acid which conducts electricity (molten or in solution) and which is decomposed as it conducts |
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| element |
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| a pure substance that consists of 1 type of atom only |
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| empirical formula |
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| the formula which gives the most simple ratio of atoms/ions in a molecule/formula unit |
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| equilibrium |
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| is reached when the forward reaction and reverse reaction are going on at the same time; at this point the amount of reactant or product does not change. |
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| half equation |
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| equation showing what goes on at each electrode in electrolysis |
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| halogen |
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| any element from group 7 in the Periodic table |
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| homologous series |
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| a group of organic compounds which all have the same general formula, similar chemical properties because they have the same functional group, have a gradual trend in physical properties, and differ by one CH2 unit. |
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| hydrocarbon |
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| a compound which has carbon and hydrogen only |
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| incomplete combustion |
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| burning in not enough oxygen |
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| indicator |
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| any chemical which can change colour when added to different chemicals, usually acids and bases |
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| intermolecular forces |
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| weak forces of attraction between molecules |
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| ion |
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| a charged atom or group of atoms (which has become charged because it has either lost or gained an electron(s)) |
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| ionic bond |
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| strong electrostatic attraction between two oppositely charged ions, formed between metals and non-metals |
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| isotopes |
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| atoms with the same number of protons and electrons but different number of neutrons; same mass number but different mass number |
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| malleable |
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| easily shaped without breaking, what metals are |
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| mass number |
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| the total number of protons and neutrons in the nucleus of an atom |
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| metallic bond |
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| attraction between positive metal ions and delocalised ?sea? of electrons |
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| mole |
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| the name given to a certain number and that number is 6.02 x 10^23. |
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| molecule |
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| a particle made up of 2 or more atoms held together by covalent bonds |
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| monomer |
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| a small molecule which can be joined together to make a long molecule called a polymer; a monomer must have a double bond or a functional group at either end |
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| % yield |
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| the actual yield expressed as percentage of the theoretical yield |
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| period |
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| horizontal row in the Periodic Table |
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| polymer |
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| a large molecule made from many small molecules that have been joined together; each polymer is made up of many repeated units |
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| precipitation |
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| a reaction between 2 salt solutions which produces an insoluble salt which sinks to the bottom of the test tube |
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| precipitate |
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| insoluble solid formed during a reaction |
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| rate of a reaction |
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| amount of change in a reactant or product over a period of time; tells us how fast a reaction is going |
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| relative atomic mass |
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| the mass of an atom as compared to 1/12th of the mass of a carbon-12 atom; it is also the average mass of all isotopes |
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| relative molecular mass |
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| the sum of the relative atomic masses (multiplied by the number of times they are in the molecule) of the atoms in the molecule |
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| relative formula mass |
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| the sum of the relative atomic masses (multiplied by the number of times they are in the formula) of the atoms or ions in the giant structure |
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| simple molecular substance |
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| substance made up of individual molecules held together by covalent bonds and has weak intermolecular forces between these molecules |
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| theoretical yield |
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| the amount of product you should obtain according to the balanced equation and calculations |
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| thermal decomposition |
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| breaking down of a compound by heating it |
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| volatile |
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| vapourises easily, low boiling point |
