Blue light (λ = 460 nm) is incident on a piece of potassium (work function Φ = 2.20 eV) What is the maximum kinetic energy of the ejected photoelectrons? (h = 6.63 x 10⁻³⁴ Js, c=3.00 x 10⁸ m/s, 1 eV = 1.60 x 10⁻¹⁹ J, and 1 nm = 10⁻⁹ m)
a. 1.0eV
b. 0.50eV
c. 0.25eV
d. 4.9eV
