\(p\,\, = \,\,\,\frac{{nhc}}{\lambda }\,\,\,\,\,\therefore \,\,n\,\, = \,\,\,\frac{{p\lambda }}{{hc}}\,\, = \,\,\,\frac{{100\,\, \times \,\,540\,\, \times \,\,{{10}^{ - 9}}}}{{6\,\, \times \,\,{{10}^{ - 34}} \times \,\,3\,\, \times \,\,{{10}^8}}}\,\, = \,\,3\,\, \times \,\,{10^{20}}\)
$\left({h}=6.63 \times 10^{-34}\, {J} \cdots\right.$, $\left.{c}=3 \times 10^{8} \,{ms}^{-1}\right)$
$( h=6.6 \times 10^{-34} \;J\cdot sec)$