Question

In a hydrogen atom, a Bohr's orbit has diameter of about $4.232\mathring{A}$. What is the maximum number of electrons that can be accommodated in this shell?

Answer 1

Answer: 8

Diameter $=4.232\mathring{A}$
$\therefore$ Radius $=2.116\mathring{A}$
Now, $r_n=0.529\times n^2\mathring{A}$ [for H-atom]
$\therefore 2.116=0.529\times n^2\mathring{A}$
$\therefore n^2=4$
$\therefore n=2$
$\therefore$ Maximum number of $e^{-}$in the second shell
$=2n^2=2\times (2{)}^2=8$