Calculate the ratio of 4th Bohr's to 2nd Bohr's orbit of `He^(+)` ion.

Explanation

To calculate the ratio of the 4th Bohr's orbit to the 2nd Bohr's orbit of the `He^(+)` ion, we can follow these steps:

### Step 1: Understand the formula for the radius of the nth Bohr orbit
The radius of the nth Bohr orbit is given by the formula:
\[ R_n = 0.529 \frac{n^2}{Z} \text{ angstroms} \]
where:
- \( R_n \) is the radius of the nth orbit,
- \( n \) is the principal quantum number (orbit number),
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