Practice question
Question
A photon of frequency 7.5 × 10¹⁴ Hz ejects an electron from a metal with a kinetic energy of 1.9878 × 10⁻¹⁹ J. What is the work function? (h = 6.626 × 10⁻³⁴ J s)
Explanation
E = hν ≈ 4.970×10⁻¹⁹ J. W₀ = E - KE ≈ 2.982×10⁻¹⁹ J.