The work function W of a metal specifies the minimum energy required to remove an electron from that metal, and is expressed as an energy per mole of electrons. For Calcium Ca, W=262 kJ mol^-1.
(a) A sample of Ca is irradiated with green light. Are electrons ejected? Justify.
(b) A sample of Ca is irradiated with light of wavelength 4.10 x 10^-7 m, and electrons are ejected. What is the speed, in m/s, of these electrons?