The elements with atomic numbers 9, 17, 35, 53, 85 are all

Options

A. noble gases
B. halogens
C. heavy metals
D. light metals.

Answer

B

Explanation

For atomic number 9, electronic configuration =`1s^(2)2s^(2)2p^(6)`
For atomic number 17, electronic configuration`1s^(2)2s^(2)2p^(6)3s^(2)3p^(5)`
The elements show ns2 np configuration which represents halogens