Question

What is likely to be principal quantum number for a circular orbit of diameter 20 nm of the hydrogen atom if we assume Bohr orbit to be the same as that represented by the principal quantum number?

• A. 10
• B. 14
• C. 12
• D. 16

Answer 1

The correct option is B 14

Diameter of orbit $=20nm=200A^o$

Radius of the orbit $=200/2=100A^o$

Radius of orbit, $r_n=0.53\times \frac{n^2}{Z}{A}^o$

$100=0.53\times \frac{n^2}{1}$

$n^2=100/0.53=189$

$n=13.74\approx 14$