Quantum Mechanics And Wave-Particle Duality - SS3 Physics Lesson Note

Quantum mechanics is the branch of modern physics that describes the behavior of particles at the atomic and subatomic level. One of the key principles of quantum mechanics is the wave-particle duality, which describes how particles can behave as both waves and particles depending on how they are observed.

In classical physics, particles are treated as discrete, point-like objects that can be accurately located in space and time. However, in quantum mechanics, particles are described by wave functions, which are mathematical representations of the probability distribution of the particle's position and momentum. These wave functions exhibit wave-like properties, such as interference and diffraction, which can only be explained in terms of waves.

The wave-particle duality is observed in many experiments, such as the double-slit experiment, where particles such as electrons or photons are fired through two slits and create an interference pattern on a screen behind the slits. This interference pattern is characteristic of waves, and can only be explained if we assume that the particles are behaving like waves.

The wave-particle duality also has implications for the Heisenberg uncertainty principle, which states that the position and momentum of a particle cannot be known with absolute certainty at the same time. This principle arises from the fact that particles have both wave-like and particle-like properties, and the more accurately we measure one property, the less accurately we can measure the other.

Overall, the wave-particle duality is a fundamental principle of quantum mechanics that describes how particles can behave as both waves and particles depending on how they are observed. It has important implications for the behavior of matter and energy at the atomic and subatomic level, and has led to many advances in technology, such as the development of transistors, lasers, and quantum computers.