Quantum mechanics

Quantum mechanics is the fundamental theory in physics that describes the behaviour of matter and energy at the scale of atoms and subatomic particles.

Key ideas

At very small scales, energy comes in discrete packets called quanta. Particles such as electrons show both particle-like and wave-like behaviour, and their properties are described by probabilities rather than certainties. Key principles include Heisenberg's uncertainty principle and superposition.

Applications

Quantum mechanics explains the structure of atoms and chemical bonds and underlies technologies such as lasers, semiconductors, MRI scanners and quantum computing.

History

It was developed in the early twentieth century by scientists including Planck, Bohr, Heisenberg, Schrödinger and Albert Einstein.

Frequently asked questions

What does quantum mechanics study?

The behaviour of matter and energy at atomic and subatomic scales.

Why is quantum mechanics important?

It explains atoms and chemistry and powers modern electronics.