After breaking of the bond of I2​ molecule, the remaining energy would be distributed uniformly to iodine atoms as their kinetic energy, i.e.E (energy of photon )= Bond energy +2× kinetic energy⇒⇒​4500×10−106.625×10−34×3×108​Ek​​=6.023×1023240×103​+2×Ek​=2.16×1020 J/atom​