| Term | Definition |
| Reactive | strong drive to become a compound |
| Potassium with water | very violent with cold water, catches fire, produces: hydrogen and potassium hydroxide |
| Sodium with water | violent with cold water, produces: hydrogen and sodium hydroxide |
| Calcium with water | less violent with cold water, produces: hydrogen and calcium hydroxide |
| Magnesium with water | very slow reaction with cold water, vigorous with steam, produces hydrogen and magnesium oxide |
| Zinc with water | quite slow with steam, produces: hydrogen and zinc oxide |
| Iron with water | slow with steam, produces: hydrogen and iron oxide (rust) |
| Copper/Silver/Gold with water | no reaction |
| Magnesium with HCl | vigorous, produces: hydrogen and solution of magnesium chloride |
| Zinc with HCl | quite slow, produces: hydrogen and zinc chloride |
| Iron with HCl | slow, produces: hydrogen and iron (ii) chloride |
| Lead with HCl | slow, only if concentrated, produces: hydrogen and lead (ii) chloride |
| Copper/Silver/Gold with HCl | no reaction even if conc. |
| Hydrogen displacement | Hydrogen is displaced by a more reactive metal |
| Competing to be the compound in solution | A metal will always displace a less reactive metal from solutions of its compounds |
| Competing for oxygen | When a metal is heated with the oxide of a less reactive metal, it acts as a reducing agent. It is always exothermic –gives out heat |
| Oxidation | gain of oxygen, loss of electrons, loss of hydrogen |
| Reduction | loss of oxygen, gain of hydrogen/electrons |
