You are given samples of three metals -sodium, magnesium and copper .suggest any two activities to arrange them in order of their decreasing reacti

explainexplain reactivity of metals on the basis of the reaction with water or acid or salt solutions.

Activity 1: we can react these metals with water. Sodium reacts violently with cold water as it is most reactive out of the three metals, Magnesium does not react with hot or cold water, it reacts with steam. Copper does not even react with steam, hence it is the least reactive of the three.

Activity 2: If the salt of any one of the metal is taken, Say for example Mg ,

We take Magnesium sulphate and react it with Na, the displacement reaction takes place, where Na displaces Mg and forms sodium sulphate
MgSO4 + 2Na → Na2SO4 + Mg

But when Cu is made to react with MgSO4, no reaction takes place. This proves that Cu is less reactive than Mg.
and Na is more reactive than Mg.

Reactivity of metals on the basis of reaction with water:

-Metals that are highly reactive react even with cold water and unreactive do not react even with steam.

Example: Sodium reacts with cold water and Iron reacts with steam and copper does not react with steam also.

1- 2 Na (s) + 2 H2O (l) → 2 NaOH (aq) + H2 (g)

2- Fe (s) + 2 H2O (l) → Fe(OH)2 (aq) + H2 (g)

3- Cu (s) + H2O (l) → No reaction.