Question

Calculate the energy associated with third orbit of He⁺.

Options

• − 4.8 × 10^-19 J

• − 1.45 × 10^-19 J

• − 19.36 × 10^-19 J

• − 9.69 × 10^-19 J

Answer 1

− 9.69 × 10^-19 J

Explanation:

He⁺ is a hydrogen-like species having Z = 2.

Using formula,

\[\mathrm{E_{n}=-2.18\times10^{-18}\left(\frac{Z^{2}}{n^{2}}\right)J}\]

Energy of the third orbit of hydrogen,

\[\mathrm{E}_3=-2.18\times10^{-18}\left(\frac{2^2}{3^2}\right)\mathrm{J}\]

∴  E₃ = − 9.69 × 10^-19 J