# What is the principal quantum no. of H-atom Orbital if the electron energy is -3.4 eV ? also report the angular momentum of electron

$(a)\;2;2.1\times10^{-34}JS^{-1}\qquad(b)\;3;4.1\times10^{-34}JS^{-1}\qquad(c)\;1;2.1\times10^{-20}JS^{-1}\qquad(d)\;4;3.2\times10^{-20}JS^{-1}$

$E_1 for H = -13.6 eV$
$E_n = \large\frac{E_1}{E_2}$
= -3.4 = $\large\frac{-13.6}{n^2}$
n = 2
Now Angular momentum (mur) = $\large\frac{n.h}{2\pi}$
$= \large\frac{2\times6.626\times10^{-34}} {2\times3.14}$
$=2.1\times10^{-34}JS^{-1}$