Question

On what basis metals are classified as reactive or non reactive

Answer 1

On the basis of Electrons we can say that;

Metals which can donate an electron easily can be classified as Reactive Metals.

Metals which can not donate an electron easily can be classified as Non-Reactive Metals.

Or
Metals having low ionization enthalpy can be termed as reactive metals and metals having high ionisation enthalpy can be termed as
non-reactive metals.