Question

The orbit number for a circular orbit of diameter 20 nm for the hydrogen atom is:

• A. 10
• B. 14
• C. 12
• D. 16

Answer 1

The correct option is B 14

Bohr radius is given as, $r_n=0.529n^2\times {10}^{-10}m$.
Given that, diameter $=20nm$

$\therefore$ Radius $=10nm=10\times {10}^{-9}m$

Using Bohr radius equation: $n^2=\frac{10\times {10}^{-9}}{0.529\times {10}^{-10}}=\frac{100}{0.529}$

$\Rightarrow n\approx 14$