Answer:
Wavelength of light in (nm) = 579 nm
Explanation:
At first you find out the amount of energy needed to just eject one electron. This is given by [tex]\frac{Energy}{Avogadro's number}[/tex]
this energy is given in question in kj/mole. This [tex]\frac{Energy}{Avogadro's number}[/tex] is the work function of cesium for each electron is equal to the planc'k einstein equation.