Question

The energy of an $e^{-}$ in an orbit in a hydrogen atom is given by $E=\frac{-constant}{n^2}\left(kJmo{l}^{-1}\right)$, which of the following properties represents the constant in the above relation?

• A. Electron affinity
• B. Ionisation energy
• C. Electronegativity
• D. Bond energy

Answer 1

The correct option is B Ionisation energy

When electron is excited from $n=1$ to $n=\infty$

$\Delta E=E_{\infty }-E_1=0-(-\frac{constant}{{\left(1\right)}^2})=constant$

The energy required to release an electron from ground level of a hydrogen atom (gaseous) is called ionisation energy.