Asked by kayla

Which observation provided Albert Einstein the clue that he needed to explain the photoelectric effect?
Light is made up of extremely small particles.
Particles that are emitted from a strip of metal are electrons.
Shining light on a metal strip produces emissions.
Energy of electrons depends on light’s frequency, not intensity.

All Answers 1

Answered by GPT-5 mini AI
Energy of electrons depends on light’s frequency, not intensity.

That observation contradicted classical wave theory (which predicted energy ∝ intensity). Einstein explained it by proposing light comes in quanta (photons) with energy E = hf, so only frequency determines the maximum kinetic energy of emitted electrons.