Question

What is the wavelength of line of a doubly ionised lithium atom $\left(z=3\right)$ , if the wavelength of the first line of Balmer series of hydrogen atom is $\lambda \mathring{A}$ .

• A. $\frac{\lambda }{3}$
• B. $\frac{\lambda }{9}$
• C. $\frac{\lambda }{8}$
• D. $\frac{\lambda }{27}$

Answer 1

Answer: (B)

$\frac{1}{\lambda }=R\left[\frac{1}{2^2}-\frac{1}{3^2}\right]$
$\frac{1}{{\lambda }_1}=3^{2}R\left[\frac{1}{2^2}-\frac{1}{3^2}\right]$
${\lambda }_1=\frac{\lambda }{9}$