QJEEAdv05Ch3e91: JEE Advanced 2005 Chemistry - Class 11 JEEAdv05Ch3e91 Solution: Find the velocity (ms -1 ) of electron in first Bohr's orbit of …

For hydrogen atom;

z = 1, n = 1

or, v = 2.18 $\times$ 10⁶ ms ^{$-$ 1}

de-Broglie's wavelength, $\lambda = {h \over {mv}}$

$= {{6.626 \times {{10}^{ - 34}}kg\,{m^2}{s^{ - 1}}} \over {9.11 \times {{10}^{ - 31}}kg \times 2.18 \times {{10}^6}\,m{s^{ - 1}}}}$

$= 3.34 \times {10^{ - 10}}\,m$

Orbital angular momentum

$= \sqrt {l(l + 1)} .\,{h \over {2\pi }}$

For 2p-orbital, l = 1

$\therefore$ Orbital angular momentum $= \sqrt 2 \,.\,h/2\pi$ .