Photoelectric effect and quanta

Combining the photoelectric effect with quantum theory demonstrated that light quanta can eject electrons from metal surfaces only if they have sufficient energy based on their frequency. This discovery helped establish the particle nature of light.
 Albert Einstein Switzerland 1905 Photoelectric effect and quanta

Combining the photoelectric effect with quantum theory demonstrated that light quanta can eject electrons from metal surfaces only if they have sufficient energy based on their frequency. This discovery helped establish the particle nature of light.