Question: What phenomenon does the photoelectric effect demonstrate?

Options:

1. Light can behave as both a wave and a particle.
2. Electrons can be emitted from a material when it absorbs light.
3. Energy is conserved in all processes.
4. Mass can be converted into energy.

Correct Answer: Electrons can be emitted from a material when it absorbs light.

Solution:

The photoelectric effect shows that when light of sufficient frequency strikes a material, it can cause the emission of electrons, demonstrating the particle-like properties of light.