Calculate the velocity of an electron present in third orbit of H atom. Also calculate number of revolutions per second round the nucleus.

Explanation

To solve the problem of calculating the velocity of an electron in the third orbit of a hydrogen atom and the number of revolutions per second around the nucleus, we can follow these steps:

### Step 1: Determine the radius of the third orbit
The radius of the nth orbit in a hydrogen atom can be calculated using the formula:
\[ r_n = n^2 \times 0.529 \times 10^{-8} \text{ cm} \]
For \( n = 3 \):
\[ r_3 = 3^2 \times 0.529 \times 10^{-8} \]
\[ r_3 = 9 \times 0.529 \times 10^{-8} \]
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