Question

The radius of an electron orbit in a hydrogen atom is of the order of

• A. $10^{-8}m$
• B. $10^{-9}m$
• C. $10^{-11}m$
• D. $10^{-10}m$

Answer 1

Answer: (D)

Radius of $n^{th}$ orbit
$r_n=0.53\frac{n^2}{Z}\mathring{A}$
Here $n=1$ and for hydrogen atom $z=1$
$\therefore r_1=0.53\frac{(1{)}^2}{1}\mathring{A}$
$=0.53\times 10^{-10}m=53pm$