Photoelectric Effect (oot an' aboot)

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Light, propagating at 186,000mps, emerges from electrically charged particles exchanging forces. It consists of oscillating electric and magnetic fields perpendicular to its direction, creating different forms of radiation across the electromagnetic spectrum. This spectrum encompasses radio waves (low-frequency), visible light (colors of the rainbow), and high-frequency Gamma Rays, invisible to the human eye.
The ““Photoelectric effect”” is where only high-frequency light wavelengths such as blue and ultraviolet, light liberate electrons in metals, outperform even intense long-wave radiation in this process. Electrons escape gaps between atomic levels ‚ making electrons liberation contingent on photon frequency (the higher, the more energy).
Each metal has its unique ‘threshold frequency’, the minimum needed for photoemission. The energy required to eject an electron is termed ‘work function’ (hfo). When a photon carries more energy than Φ, the excess becomes kinetic energy for the freed electron. The photoelectric equation is described as: hf = Φ – Ek

hf = Energy of photon. Energy calculated by joules.
Φ = Minimum energy required for photoemission.
Ek = Maximum Kinetic Energy of ejected electron

The photoelectric effect can explain a biological oddity. The retina at the back of our eyes is lined with photoreceptor cells converting light photons into electrical signals using retinal, which changes its structure when exposed to light. Although the human body produces a million times more infrared radiation, we can’t perceive it because these infrared photons lack sufficient energy to stimulate the retinal. Thus, light has a mathematical explanation, as we can’t perceive most electromagnetic spectrum wavelengths.

— Callum Alexander (S6)