Question

Which of the following elements is the most reactive?

A. At
B.Cl
C.I
D.Br

Answer 1

B. Cl.

Step-by-step explanation:

These are Group 7 elements whose reactivity reduces as you go down the group. Chlorine has a smaller atoms than the rest and has a stronger tendency to grab an electron in its valency shell. This is because its nucleus is closer to the outer electrons than the other elements.