v=Frequency=1.2×10^15Hz
Now
[tex]\\ \sf{:}\!\!\implies E=hv[/tex]
h is Planck's constant
[tex]\\ \sf{:}\!\!\implies E=6.626\times 10^{-34}Js\times 1.2\times 10^{15}s^{-1}[/tex]
[tex]\\ \sf{:}\!\!\implies E=7.95\times 10^{-19}J[/tex]
[tex]\\ \sf{:}\!\!\implies E=79.5\times 10^{-18}J[/tex]
[tex]\\ \sf{:}\!\!\implies E=79.5am[/tex]
