Iodine molecule dissociates into atoms after absorbing light of 450$0^{\mathrm{o}}$ A . If one quantum of radiation is absorbed by each molecule, calculate the kinetic energy of Iodine atoms. (Bond energy of ${\mathrm{I}}_2=240\mathrm{KJ} {\mathrm{mol}}^{-1}$

Given bond energy of

${\mathrm{I}}_2=240\times {\mathrm{KJmol}}^{-1}$

$=240\times {10}^3\mathrm{J} {\mathrm{mol}}^{-1}$

Hence, bond energy of each molecule

$\frac{6.623\times {10}^{-34}-3\times {10}^8}{4500\times {10}^{-10}}$

$=4.417\times {10}^{-19}\mathrm{J}$

K.E of one ${\mathrm{I}}_2$molecule=$4.417\times {10}^{-19}-8.965\times {10}^{-19}$

$=0.432\times {10}^{-19}$

K.E of each atom=$\frac{0.482\times {10}^{-19}}{2}=0216\times {10}^{-19}J$

$=2.16\times {10}^{-20}\mathrm{J}$