Answer
(a)$\lambda=163.03nm$
(b)$f=1.84\times10^{15}Hz$
(c) ultraviolet rays
Work Step by Step
Given that dissociation energy of cynogen molecule is $E=1.22\times10^{-18}J$
suppose energy is provided by single photon .
frequency of photon $f$
and wavelength of photon is $\lambda$
From Plank's hypothesis
$E=hf=\frac{hc}{\lambda}$ , here $c$ is speed of light
(a) wavelength calculatio
$E=\frac{hc}{\lambda}$
$\lambda=\frac{hc}{E}$
putting $h=6.63\times10^{-34}J.s$, $E=1.22\times10^{-18}J$, $c=3\times10^{8}m/s$
$\lambda=\frac{6.63\times10^{-34}J.s\times3\times10^{8}m/s}{1.22\times10^{-18}J} =16.303\times10^{-8}m=163.03\times10^{-9}m$
$\lambda=163.03nm$
(b) frequency
$E=hf$
$f=\frac{E}{h}$
putting $h=6.63\times10^{-34}J.s$, $E=1.22\times10^{-18}J$
$f=\frac{1.22\times10^{-18}J}{6.63\times10^{-34}J.s}=0.18401\times10^{16}/s$
$f=1.84\times10^{15}Hz$
(C) as its frquency is close to $10^{16}Hz$ it lies in the range of ultraviolet rays.
