If an electron drops from n = 4 to n = 2 in `Li^(2+)` then would the released wavelength lie in the visible region?

Explanation

To determine whether the wavelength released when an electron drops from n = 4 to n = 2 in Li²⁺ lies in the visible region, we can follow these steps:

### Step 1: Identify the formula for wavelength in hydrogen-like atoms
The wavelength of light emitted during an electron transition in hydrogen-like atoms can be calculated using the formula:
\[ \frac{1}{\lambda} = RZ^2 \left( \frac{1}{n_1^2} - \frac{1}{n_2^2} \right) \]
where:
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