\(=\frac{ N _A hc }{\lambda}\)
\(=\frac{6 \times 10^{23} \times 6.63 \times 10^{-34} \times \gamma \times 10^8}{9 \times 10^{-7}}\)
\(=1.326 \times 10^5\, J\, mol ^{-1}\)