Question

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

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

Answer 1

Answer: (B)

halogens

These atomic number gives the electronic configuration $n{s}^{s}n{p}^5$ which are of halogen group or ${17}^{th}$ group.