Question

If ${\lambda }_1$ and ${\lambda }_2$ denote the wavelength of de Broglie waves for electrons in Bohr’s first and second orbits in the hydrogen atom,then ${\lambda }_1/{\lambda }_2$ will be:

• A. 2
• B. 1/2
• C. 4
• D. 1/4

Answer 1

The correct option is B

1/2

$\lambda =\frac{h}{\sqrt{2Em}}or\lambda \infty \frac{1}{\sqrt{E}}\frac{{\lambda }_1}{{\lambda }_2}=\sqrt{\frac{E_2}{E_1}}=\sqrt{\frac{3.4}{13.6}}=\frac{1}{2}$