Question

Find the minimum frequency of light which can ionize a hydrogen atom

• A. $3.28\times 10^{15}Hz$
• B. $5\times 10^{15}Hz$
• C. $91.1Hz$
• D. None of these

Answer 1

Answer: (A)

Ionization energy of H-atom $=13.6eV$
$\therefore h{f}_{min}=13.6eV$
$\therefore f_{min}=\frac{13.6\times 1.6\times 10^{-19}}{6.63\times 10^{-34}}=3.28\times 10^{15}Hz$