Solution:
Concept- When a metal reacts with a base, it forms the corresponding salt along with the evolution of hydrogen gas, and the reaction between the base and the metal will be intense or absent depending on the position of the metal in the reactivity series.Now, a reactivity series is a series of metals arranged in order of reactivity from highest to lowest. The most reactive metal is placed at the top of the series and the least reactive metal is placed at the bottom of the series.
Now, when a base reacts with a metal, the corresponding salt is formed along with the evolution of gases, and also, the greater the difference between the metals in the reactivity series, the faster the rate of reaction.
Thus, the greater the difference between the stability of the molecules, the more rapidly they will react in order to achieve stability. If the difference between the stabilities is smaller than the atoms will have similar stabilities whether they react or not. So they won't react as vigorously to settle down.
Hence, the correct answer is 2.
