Question

The total number of electrons in a principal energy shell is designated by

• A.
  $N$
• B.
  $2n+1$
• C.
  $d_{xy}$
• D.
  $2n^2$

Answer 1

The correct option is D

$2n^2$
In a particular principal energy shell the total number of electrons is calculated by$2n^2$. It was given by Bohr-Bury. n is the principal quantum number.

$For2s,n=2For4p,n=4,etc..,$