Answer
a) $n=5$
b) $L=4.7256\times 10^{-34}J.s$
c) 14
Work Step by Step
(a) We know that
$E_{n}=\frac{-13.6}{n^2}eV$
$\implies -0.544=\frac{-13.6}{n^2}$
This simplifies to:
$n=5$
(b) We know that
$L=\sqrt{l(l+h)}\frac{h}{2\pi}$
We plug in the known values to obtain:
$L=\sqrt{4(4+1)}(\frac{6.63\times 10^{-34}}{2\times 3.14})$
$L=4.7256\times 10^{-34}J.s$
(c) For a given value of $l$, the possible values of $m_s$ are $2(2l+1)$. In the given scenario, $l=3$, so the number of states in this sub shell is:
$2[2(3)+1]=2(6+1)=14$
