Question

Ionization energy is the energy needed to eject an electron from an atom or ion. Calculate the ionization energy, I E , of the one‑electron ion He + . The electron starts in the lowest energy level, n = 1 .

Answer 1

Answer:

Ionization energy of $He^+$ is 54.4 eV.

Explanation:

$E_n=-13.6\times \frac{Z^2}{n^2}eV$

where,

$E_n$ = energy of  orbit

n = number of orbit

Z = atomic number

Energy of n = 1 in an hydrogen like atom:

$E_1=-13.6\times \frac{2^2}{1^2}eV=-54.4 eV$

Energy of n = ∞ in an hydrogen like atom:

$E_{\infty }=-13.6\times \frac{2^2}{\infty ^2}eV=0$

Ionization energy of $He^+$ =

$E=E_{\infty }=E_1=0 - (-54.4 eV)=54.4 eV$