Q. If elements with principal quantum number $n$> 4 not allowed in nature, the number of possible elements would be
A) 60
B) 32
C) 4
D) 64
Explanation
(a) Number of possible elements
$= 2(1^{2} + 2^{2} + 3^{2} + 4^{2})$
$= 2(1 + 4 + 9 + 16) = 60$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.