Define photoelectric work function. How is it related to thresold frequency?

Explanation

**Step-by-Step Solution:**

1. **Definition of Photoelectric Work Function:**
The photoelectric work function, denoted as \( \phi_0 \), is defined as the minimum amount of energy required to eject an electron from the surface of a photosensitive material when it is exposed to light. This energy is specific to each material and represents the energy barrier that must be overcome for an electron to escape from the metal surface.

2. **Understanding the Photoelectric Effect:**
The photoelectric effect occurs when light (or electromagnetic radiation) strikes a metal surface and causes the ejection of electrons from that surface. For this effect to take place, the energy of the incident photons must be equal to or greater than the work function of the material.

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