Radiation with a wavelength of 238 nm shines on a metal surface and ejects electrons that have a maximum speed of 3.75x10⁵ m/s.
Which of the following metals is it? (The values in parentheses are the work functions)
a. Potassium (2.24 eV)
b. Calcium (2.71 eV)
c. Gold (4.82 eV)
d. Uranium (3.63 eV