When sunlight hits an electron, several outcomes are possible depending on the energy of the incoming photons:

• Absorption of energy and excitation: The electron can absorb energy from the photon, causing it to move to a higher energy level within the atom. This is an excitation process where the electron remains bound but in an elevated energy state

• Ejection from the atom (Photoelectric effect): If the photon has enough energy (above a threshold frequency), the electron can absorb this energy and be completely ejected from the atom as a photoelectron. This is the photoelectric effect, where electrons are emitted from a material upon exposure to sufficiently energetic light

• No interaction or scattering: In some cases, photons may scatter off electrons without being absorbed, causing the electrons to oscillate and re-radiate energy in different directions. This is known as electron scattering and does not necessarily lead to electron ejection

• Energy transfer to free electrons: Photons can also transfer energy to free electrons (not bound to atoms), increasing their kinetic energy. These energetic electrons may later release energy as new photons

The photoelectric effect notably shows that electrons are emitted only when the photon energy exceeds a material-specific work function, regardless of light intensity, which classical wave theory could not explain. This led to the understanding that light consists of discrete packets of energy called photons

. In summary, when sunlight hits an electron, it can absorb the energy and either jump to a higher energy state or be ejected from the atom if the photon energy is sufficient, or it may scatter the photon without absorption depending on conditions.