| A | B |
|---|
| chemical reactions | make a new substance |
| a chemical change | cannot be reversed |
| melting and boiling are | physical changes |
| during a physical change | no new substances are made |
| bubbles | show effervescence |
| chemicals which react together | are reactants |
| the substance which are made | are products |
| word equations | show what happens in a chemical reaction |
| iron + oxygen | = iron oxide |
| two elements react to form a | compound |
| calcium + chlorine | = calcium chloride |
| in a compound, elements are chemically joined by | bonds |
| when fuels are completely burned in oxygen | carbon dioxide and water are formed |
| carbon and oxygen atoms join to form | carbon dioxide |
| hydrogen and oxygen atoms join to form | water |
| tests for carbon dioxide | limewater |
| test for oxygen | re-lights a glowing splint |
| test for hydrogen | squeaky pop |
| test for chlorine gas | blue litmus turns red and then bleaches (goes white) |
| turns from blue to pink in the presence of water | cobalt chloride paper |
