Question

How many times does the electron go round the first Bohr orbit in a second?

• A. $6.57\times {10}^5$
• B. $6.57\times {10}^{10}$
• C. $6.57\times {10}^{13}$
• D. $6.57\times {10}^{15}$

Answer 1

The correct option is D $6.57\times {10}^{15}$

Frequency $\left(\nu \right)=\frac{v}{2\pi r}$

where, v is velocity of electron and r is radius of first Bohr orbit.

$\Rightarrow \nu =\frac{2.2\times {10}^6}{2\pi (0.5287\times {10}^{-10}m)}=6.57\times {10}^{15}$

Therefore, D is correct option.