The work function of sodium metal is 4.41 $$ \times $$ 10^–19 J. If photons of wavelength 300 nm are incident on the metal, the kinetic energy of the ejected electrons will be (h = 6.63 $$ \times $$ 10^–34 J s; c = 3 $$ \times $$ 10⁸ m/s) ________ × 10^–21 J.