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calculate the wavelength of light required to break the bond between two chlorine atoms in a chlorine molecule.the cl-cl bond energy is 243Kj mol-1

1 KJ /mol = 0.0167 × 10^-19 J / molecule

?  243 KJ /mol = 0.0167 × 243 × 10^-19

                         = 4.067 × 10^-19 J /molecule.

According to Planck law,

Note:

h - Planck constant = 6.625 × 10^-3

c - velocity of light = 3 × 10⁸ m/s

nm - nanometer = 10^-9 m

      - unit of wavelength