The work function of sodium metal is 4.41× 10 ⁻¹⁹ J . If the photons of wavelength 300 nm are incident on the metal, the kinetic energy of the ejected electrons will be h=6.63× 10 ⁻³⁴ Js; c=3× 10 ⁸ m/s

Explanation

The work function of sodium metal (Φ) = 4.41 × 10^-19 J

Wavelength (λ) = 300 nm = 300 × 10^-9 m

Planck's constant (h) = 6.63 × 10^-34 J s

Speed of light (c) = 3 × 10⁸ m/s

We know,

K_Emax = [hc / λ] - Φ

Therefore,

K_Emax = [ (6.63 × 10^-34) × (3 × 10⁸) / (300 × 10^-9) ] - (4.41 × 10^-19)

K_Emax = 6.63 × 10^-19 - 4.41 × 10^-19

K_Emax = 222 × 10^-21 J