When a metal is exposed to photons at a frequency greater than its threshold frequency, what is observed according to the photoelectric effect?

• A. Electrons are emitted from the metal surface.
• B. The metal emits visible light.
• C. No electrons are emitted regardless of the frequency.
• D. The metal becomes magnetized.

Answer: (A)

Verified step by step guidance

1. Understand the photoelectric effect: When light (photons) shines on a metal surface, electrons can be ejected if the photons have enough energy.
2. Recall that the energy of a photon is given by the equation \(E = h \times f\), where \(h\) is Planck's constant and \(f\) is the frequency of the light.
3. Identify the threshold frequency \(f_0\) as the minimum frequency needed for photons to have enough energy to overcome the work function (the energy needed to release an electron from the metal).
4. If the frequency of the incident photons \(f\) is greater than the threshold frequency \(f_0\), then the photon energy \(E = h \times f\) is sufficient to eject electrons from the metal surface.
5. Therefore, according to the photoelectric effect, when the frequency of the incident light is greater than the threshold frequency, electrons are emitted from the metal surface.