The work function of sodium metal is $4.41 \times 10^{-19} \mathrm{~J}$. If photons of wavelength $300 \mathrm{~nm}$ are incident on the metal, the kinetic energy of the ejected electrons will be $\left(h=6.63 \times 10^{-34} \mathrm{~J} \mathrm{~s} ; c=3 \times 10^{8} \mathrm{~m} / \mathrm{s}\right)$
$\times 10^{-21} \mathrm{~J}$