| A | B |
|---|
| agents of change | heat energy, light energy, electricity, mixing |
| sublimation | the change of a substance from a solid state to a vapour state |
| decomposition | the process whereby a substance is spilt into two or more simpler substances |
| products from the decomposition of sugar | water and carbon |
| products from the decomposition of water by electricity | oxygen and hydrogen |
| products of photosynthesis | glucose and oxygen |
| photosynthesis | a reaction that occurs in the presence of light |
| useful chemical reactions | digestion, respiration and photosynthesis |
| chemical reaction that is not welcome | rusting |
| needed for the combustion of fuels | oxygen |
| melting | the change from a solid state to a liquid state |
| electroplating | coating an object with a metal by using electricity |
| undergo sublimation when heated | dry ice, ammonium chloride and iodine |
| reactants of photosynthesis | water and carbon dioxide |
| reactants of respiration | glucose and oxygen |
| main product of respiration | energy |
| waste products of respiration | carbon dioxide and water |
| products obtained when limestone is heated | calcium oxide and carbon dioxide |
| the gas that turns limewater milky | carbon dioxide |
| the gas that relights a glowing splint | oxygen |
| the gas that extinguishes a lighted splint and gives a 'pop' sound | hydrogen |
| the substance that becomes a purple vapour when heated | iodine |
| examples of exothermic reactions | combustion and respiration |
| examples of endothermic reactions | photosynthesis and decomposition of carbonates |
| An exothermic reaction is one in which | energy is released to the surroundings. |
| An endothermic reaction is one in which | energy is absorbed from the surroundings. |
| gaseous pollutants produced during the combustion of fossil fuels in power stations and industries | sulphur dioxide |
| poisonous gas released during the incomplete combustion of fossil fuels | carbon monoxide |
| gas that accounts for the slightly acidic nature of rain | carbon dioxide |
| dissolve in rain water to form acid rain | oxides of nitrogen and sulphur dioxide |
