2.30 describe how reactions with water and dilute acids can be used to deduce the following order of reactivity: potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper

Metals high up in the series (potassium, sodium, lithium and calcium) react very vigorous with water.

Metals in the middle (magnesium, zinc and iron) react with steam but don't react with cold water.

Copper won't react with either steam or water.

The more reactive the element is with water and dilute acid, the further up the series the element is positioned.