Summary

The Photoelectric Effect is the phenomenon in which electrons are emitted from the surface of a metal when it is exposed to light. This effect is only observed when the frequency of the light is above a certain threshold, known as the threshold frequency. The kinetic energy of the emitted electrons is directly proportional to the frequency of the light, and is independent of the intensity of the light. The Photoelectric Effect is important because it was the first experimental evidence to support the idea that light can behave as both a wave and a particle, known as the wave-particle duality.

Energy levels in atoms refer to the specific allowed energies that an electron in an atom can have. These energy levels are determined by the electric field created by the nucleus and other electrons in the atom, and are quantized, meaning that the allowed energy levels are discrete rather than continuous. The energy levels are typically represented by the letters n, where n can be any positive integer. The lowest energy level is known as the ground state, and higher energy levels are known as excited states. When an atom absorbs energy, an electron can be excited from the ground state to a higher energy level, and when it loses energy, an electron can return from an excited state to the ground state, emitting a photon of light in the process.

Wave-particle duality is the concept in physics that describes the behavior of particles and waves, and the relationship between them. It states that all particles exhibit both wave-like and particle-like properties, depending on the circumstances. This duality arises from the fact that the equations of quantum mechanics, which describe the behavior of particles on a very small scale, contain both wave-like and particle-like terms. The concept of wave-particle duality has been confirmed experimentally through observations such as the double-slit experiment and the Photoelectric Effect. It is a fundamental principle of quantum mechanics and is important for understanding the behavior of subatomic particles.