For hydrogen ; $n = 1$ and $z = 1$ therefore
${r_H} = 0.529\,{\mathop A\limits^o }$
For $B{e^{3 + }}:\,Z = 4$ and $n = 2$ Therefore
${r_{B{e^{3 + }}}} = \frac{{0.529 \times {2^2}}}{4} = 0.529\,{\mathop A\limits^o }$.
$\mathop {CH_3^ + }\limits_{\rm{I}} $ $\mathop {{H_3}{O^ + }}\limits_{{\rm{II}}} $ $\mathop {N{H_3}}\limits_{{\rm{III}}} $ $\mathop {CH_3^ - }\limits_{{\rm{IV}}} $
[ઉપયોગ કરો : $\sqrt{3}=1.73, h =6.63 \times 10^{-34} Js$ $m _{ e }=9.1 \times 10^{-31} kg ; c =3.0 \times 10^{8} ms ^{-1}$ $\left.1 eV =1.6 \times 10^{-19} J \right]$
$(d) n = 3, l = 2, m = 1\, (e) n = 3, l = 2, m = 0$