| A | B |
|---|
| compounds are made from | more than one element chemically joined together |
| when a new substance is formed | this is known as a chemical change |
| chemical changes are | difficult to reverse |
| molecules are made from | atoms joined by chemical bonds |
| water is a compound made from | the elements hydrogen and oxygen |
| carbon dioxide is a compound made from | the elements carbon and oxygen |
| salt | sodium chloride |
| rust | iron oxide |
| copper sulfate | copper, sulfur, oxygen |
| sugar | carbon, hydrogen, oxygen |
| carbon monoxide | CO |
| hydrochloric acid | HCl |
| sodium hydroxide | NaOH |
| Calcium hydroxide | Ca(OH)2 |
| Magnesium oxide | MgO |
| a mixture is formed | when 2 or more substances are mixed without any chemical reaction taking place |
| process used to separate some compounds | electrolysis |
