1. When light of wavelength 322 nm falls on a potassium surface, electrons are emitted that have a maximum kinetic energy of 1.35 eV. What is the work function of potassium? The speed of light is 3 × 108 m/s and Planck’s constant is 6.63 × 10−34 J · s. Answer in units of eV.

2. What is the cutoff wavelength of potassium? Answer in units of nm.

3.What is the threshold frequency for potassium? Answer in units of Hz.