Question

The wave length of first member of Balmer series of a hydrogen atom is nearly (The value of Rydberg constant is $1.08\times {10}^7{m}^{-1})$

• A. $4400A^0$
• B. $5500A^0$
• C. $6600A^0$
• D. $7700A^0$

Answer 1

The correct option is C

$6600A^0$

$n_1=2$ $n_2=3$

$\frac{1}{\lambda }=R[\frac{1}{4}-\frac{1}{9}]$

$\lambda =\frac{36}{5R}=\frac{36}{5\times 1.08\times {10}^7}m$

= $\frac{36}{5\times 1.08}\times {10}^{-7}m$

$\approx 6600A^0$