Answer:
φ = 13.43 x 10⁻¹⁹ J = 8.4 eV
Explanation:
Using the Einstein's Photoelectric equation:
Energy of Photon = Work Function + Kinetic Energy of Electron
[tex]\frac{hc}{\lambda} = \phi + K.E[/tex]
where,
h = Plank's Constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength = 124 nm = 1.24 x 10⁻⁷ m
φ = work function = ?
K.E = Kinetic Energy of Electrons = (4.16 eV)([tex]\frac{1.6\ x\ 10^{-19}\ J}{1\ eV}[/tex]) = 2.6 x 10⁻¹⁹ J
Therefore,
[tex]\frac{(6.625\ x\ 10^{-34}\ J.s)(3\ x\ 10^8\ m/s)}{1.24\ x\ 10^{-7}\ m} = \phi + 2.6\ x\ 10^{-19}\\\\\phi=16.03\ x\ 10^{-19}\ J - 2.6\ x\ 10^{-19}\ J[/tex]
φ = 13.43 x 10⁻¹⁹ J = 8.4 eV
