Q. Which element out of $He,\ Ar,\ Kr\ and\ Xe$ forms least number of compounds?
A) $Kr$
B) $Xe$
C) $Ar$
D) $He$
Explanation
(d)
Due to (i) Small atomic size (ii) High ionization energy (iii) Absence of $d$-orbital, helium does not form any compound
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.