A metal 'X' reacts readily with the oxygen in the air but does not react with cold or hot water. The metal 'X' can be:

Choose a metal out of the following which reacts with hot water, not with cold water:

Sodium, Magnesium, Iron

From the metals copper, iron, magnesium, sodium, and zinc, select a different metal that does not react with cold water but reacts with steam when heated.

Also, arrange the given metals in decreasing order of reactivity.

From the metals copper, iron, magnesium, sodium and zinc, select a different metal in each case which:
(i) does not react with dilute hydrochloric acid.
(ii) can form 2+ and 3+ ions.
(iii) has a hydroxide that reacts with both acids and alkalis.
(iv) does not react with cold water but reacts with steam when heated.
Arrange the metals in increasing order of reactivity.