Quantum mechanics is the branch of physics that studies the behavior of matter and energy in the presence of an observer. It is the foundation of modern physics and the theory of the wave-particle duality.

Quantum mechanics predicts that particles can exist in more than one state at the same time. This means that a particle can be in two places at the same time, or it can have two different energies at the same time. The behavior of a particle in a quantum state is governed by the laws of probability.

Quantum mechanics has been used to explain a wide variety of physical phenomena, including the behavior of subatomic particles, atoms, and molecules. It has also been used to develop technologies such as lasers and transistors.

## Other related questions:

### Q: What does quantum mechanics focus on?

A: Quantum mechanics is the branch of physics that studies the behavior of matter and energy in the presence of an observer. It is the foundation of modern physics and the theory of the wave-particle duality.

### Q: What does quantum theory tell us about reality?

A: Quantum theory is a branch of physics that explores the very small world of particles at the atomic and subatomic level. In the quantum world, the rules of classical physics no longer always apply. This means that subatomic particles can exist in more than one state at the same time. Quantum theory can help us to understand the strange and seemingly bizarre behavior of particles on a very small scale.

### Q: Are quantum events predictable?

A: It is impossible to predict the outcome of a quantum event with certainty. However, the laws of quantum mechanics allow us to calculate the probability of various outcomes.