| A | B |
|---|
| In chemical reactions the starting materials | are reactants |
| The substance produced by a chemical reaction | is known as the product |
| The total mass of the reactants | is equal to the total mass of the products |
| In exothermic reactions energy is given off | in the form of heat or light |
| Endothermic reactions | require an input of heat |
| Decomposition is the opposite of | synthesis |
| The idea that mass and energy are interchangeable | was first suggested by Albert Einstein |
| A metal so soft that it can be cut with a knife | Sodium |
| A pale yellow-green gas | Chlorine |
| A chemical reaction between powdered cement and water | causes concrete to harden |
| In synthesis reactions | a compound is formed |
