Answer : The work function of this metal is, [tex]5.81\times 10^{-19}J[/tex]
Explanation : Given,
Wavelength of light = [tex]342nm=342\times 10^{-9}m[/tex]
Formula used :
[tex]E=h\nu_o=\frac{hc}{\lambda}[/tex]
where,
E = work function of metal
h = Planck's constant = [tex]6.626\times 10^{-34}Js[/tex]
[tex]\nu_o[/tex] = threshold frequency
[tex]\lambda[/tex] = wavelength of light
c = speed of light = [tex]3\times 10^8m/s[/tex]
Now put all the given values in this formula, we get the value of work function of this metal.
[tex]E=\frac{hc}{\lambda}[/tex]
[tex]E=\frac{(6.626\times 10^{-34}Js)\times (3\times 10^8m/s)}{(342\times 10^{-9}m)}[/tex]
[tex]E=5.81\times 10^{-19}J[/tex]
Therefore, the work function of this metal is, [tex]5.81\times 10^{-19}J[/tex]