Which s larger, an `He^(+)` ion with electron in 3rd orbit or `Li^(2+)` ion with electron in 5th orbit ?

Explanation

To determine which ion is larger, we will calculate the radius of the orbits for both the \( \text{He}^+ \) ion in the 3rd orbit and the \( \text{Li}^{2+} \) ion in the 5th orbit using Bohr's model of the atom.

### Step 1: Write the formula for the radius of the nth orbit
According to Bohr's model, the radius \( r_n \) of the nth orbit is given by the formula:
\[ r_n = \frac{0.529 \, n^2}{Z} \, \text{Å} \]
where \( n \) is the principal quantum number (the orbit number) and \( Z \) is the atomic number of the element.
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