Question

When the electron of hydrogen atom comes from infinity into the first orbit, then the value of wave number $\left( \frac{1}{\lambda} \right)$ is -

• A. 109700 cm^–1
• B. 1097 cm^–1
• C. 109 cm^–1
• D. None of these

Answer 1

Answer: (A)

109700 cm^–1

Answer 2

$\frac{1}{\lambda}$ = 1.097 × 10⁷$\left( \frac{1}{1^{2}} - \frac{1}{\infty} \right)$

\$\frac{1}{\lambda}$ = 1.097 × 10⁷m^–1

= 1.097 × 10⁵ cm^–1

= 109700 cm^–1