Question

A,b,c have 3,4,2 electrons in their outermost shell give the group number and the valency

Answer 1

for A
valence electrons = 3
so group no. = 13
valency = +3

for B
valence electrons = 4
group no = 14
valency = +4

for C
valence electrons = 2
group no. = 12
valency = +2