Q.

Assertion: Reactivity Series is an arrangement of element based on their reactivity.
Reason: Reactivity Series is used to separate elements based on their reactivity.

1 Both assertion and reason are correct and reason is the correct explanation of assertion.  
2 Both assertion and reason are correct, but reason is not the correct explanation of assertion.  
3 Assertion is true, but reason is false.  
4 Assertion is false, but reason is true  

Ans.

(1)

Reactivity Series is an arrangement of element based on their reactivity in the increasing or the decreasing order and this series is used to separate elements based on their reactivity. Thus both assertion and reason are correct and reason is the correct explanation of the assertion.