Q. The elements with atomic numbers 9, 17, 35, 53, 85 are all
A) Halogens
B) Noble gases
C) Heavy metals
D) Light metals
Explanation
(a)
These atomic numbers give the configuration $ns^{2}np^{5}$ which is of halogen group or VIIth group
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.