Question

a) The order of reactivity of the metals K, Na, Cu, Ag is:
i. Na > K > Cu > Ag
ii. Na > K > Ag > Cu
iii. K> Na > Cu > Ag
iv. K> Na > Ag > Cu​

Answer 1

iii. K>Na>Cu>Ag

Explanation:

Alkali metals i.e. Group 1A metals are most reactive. among them, the reactivity increases while moving down in a group because the size of atom increases and force of attraction between outermost electron and nucleus decreases. So, K is more reactive than Na.

Also in reactivity series, CHAPA metals are placed in the decreasing order of reactivity below hydrogen. Here, Cu is placed above Ag.

So order is K>Na>Cu>Ag