Balancing Chemical Equations

Balancing chemical equations

1. Complete the following sentences, using the words or groups of words in the box below. You may use some words more than once.

|• as small as possible |• decrease |• molecules |• quantities |
|• balance |• different |• nature |• rearranging |
|• bonds |• equal |• never |• release of a gas |
|• characteristic properties |• heat |• new elements |• rules |
|• check |• increase |• nuclear |• signs |
|• chemical |• law of conservation |• nucleus |• state |
|• chemical equation |of mass |• physical |• stoichiometry |
|• coefficient |• mass of products |• precipitate |• subscript symbols |
|• colour |• mass of reactants |• products |• transformed |
|• counting |• molar mass |• proportions |• whole numbers |

a) There are three types of changes in matter: ________________________ changes, chemical changes and ________________________ changes.

b) A physical change occurs when the form or the ________________________ of a substance is changed. For example, when liquid water is cooled, it becomes ice. Whether water is in liquid form or in the form of ice, the ________________________ that form