Question

Which of the following expressions represents the spectrum of Balmer series (If n is the principal quantum number of the higher energy level) in a hydrogen atom?

• A. $v̅=\frac{R(n-1)(n+1)}{n^2}c{m}^{-1}$
• B. $v̅=\frac{R(n-2)(n+2)}{4n^2}c{m}^{-1}$
• C. $v̅=\frac{R(n-2)(n+2)}{n^2}c{m}^{-1}$
• D. $v̅=\frac{R(n-1)(n+1)}{n^2}c{m}^{-1}$

Answer 1

The correct option is B $v̅=\frac{R(n-2)(n+2)}{4n^2}c{m}^{-1}$

$\stackrel{-}{v}=R(\frac{1}{n_f^2}-\frac{1}{n_i^2})c{m}^{-1}$
for Balmer series $n_i=2$ and iven that$n_i=n$
$\stackrel{-}{v}=R(\frac{1}{2^2}-\frac{1}{n^2})c{m}^{-1}$
$v̅=\frac{R(n-2)(n+2)}{4n^2}c{m}^{-1}$