In the photoelectric effect, electrons are never emitted from a metal if the fre

Question

In the photoelectric effect, electrons are never emitted from a metal if the frequency of the incoming light is below a certain threshold value. This is because:

The number of photons in low-frequency light is too small to eject electrons.

Photons of lower-frequency light don't have enough energy to eject an electron.

The electric field of low-frequency light does not vibrate the electrons rapidly enough to eject them.

Low-frequency light does not penetrate far enough into the metal to eject electrons.

Explanation / Answer

Frequency of a photon is proportional to the energy of that photon E=hf, so higher frequency, higher energy.

When a photon hits an electron, the electron absorbs all of the energy in the photon, but will release this energy quickly, too fast to absorb multiple photons at once, so if the energy of a single photon isnt enough for an electron to overcome the attractive forces of the positive nucleus and escape, then the electron cant escape. no matter how many of the photons you fire at the material.

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