Question

The electronic configuration of four elements A,B,C,D A=1s2 2s2. B=1s2 2s2 2p6 . C= 1s2 2s2 2p6 3p2 . D= 1s2 2s2 2p6 3s1
a) which element belongs to same period
b) which element belongs to same group.
C) which element belongs to group 17. D) to which element family does the element 'D' belongs

Answer 1

we know
configuration nt^x
n represent no of period
t represent block (e.g s, p, d, f)
x represent group
a) A, B, are 2nd period elements and C, D are elements of 3rd period.

b) A and C are same group elements

c) no elements in group 17

d) alkali metal (s -block) family