The ionization energy of `He^(+)` is `8.72 xx 10^(-18)J "atom"^(-1)`. Calculate the energy of first stationary state of `Li^(2+)`.

Explanation

To calculate the energy of the first stationary state of \( \text{Li}^{2+} \), we can use the formula for the energy of an electron in a hydrogen-like atom:

\[ E_n = -\frac{kZ^2}{n^2} \]

### Step 1: Understand the Ionization Energy
The ionization energy of an atom is the energy required to remove an electron from the ground state (first stationary state) to an infinite distance (where the electron is free). For helium ion \( \text{He}^{+} \), the ionization energy is given as \( 8.72 \times 10^{-18} \, \text{J} \).
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