of the three metals X, Y and Z, X reacts with cold water, Y with hot water and Z with steam only. Identify X, Y and Z and also arrange them in order of increasing reactivity.

Explanation

The answer is based on the relative positions of the metals in the reactivity series. The activity with water decreases down the series.
• Metals X is Na or K • Metal Y is Mg or Ca • Metal Z is Al or Fe.
Order of increasing reactivity : `Z lt Y lt X`.