Question

8. The element A, B, C, D and Ehave atomic number
9, 11, 17, 12 and 13 respectively. Which pair of
elements belong to the same group?
​

Answer 1

A=2,7

B=2,8,1

C=2,8,7

D=2,8,2

E=2,8,3

elements A & C belong to the same group as they have the same number of valence electrons.