Answer: particle.
- A particle
- B a liquid
- C a gas
- D a solid
Correct answer: A. particle
Explanation: Light shows a dual wave–particle nature.
In the photoelectric setup, light striking the metal plate ejects electrons that cross the evacuated tube to the collector, producing a measurable current on the ammeter.
Concept context
Photoelectric effect, de Broglie waves, Bohr's model, atomic spectra.