[Rhc=13.6 eV, $\mathrm{hc}=1242 \mathrm{eV} \mathrm{nm}, \mathrm{h}=6.6 \times 10^{-34} \mathrm{J-s}$ અને હાઈડ્રોજન પરમાણુનું દળ $\sim 1.6 \times 10^{-27} \mathrm{~kg}$ લો.]
$\left(\frac{1}{4 \pi \epsilon_0}=9 \times 10^9 \mathrm{SI}\right.$ એકમ $\alpha$ કણનું દળ $=$ $\left.6.72 \times 10^{-27} \mathrm{~kg}\right)$