Quantum Mechanics Quantum Mechanics Observation of the behavior of elementary particles Quantum mechanics deals with the behavior of fundamental particles, which cannot be explained under classical Newtonian physics. Together with the theory of relativity, quantum mechanics comprises an extremely important approach to understanding the universe.
All matter is composed of atoms.
However, it is postulated that there exist even smaller, subatomic particles which make up atoms. Observation of the behavior of these atoms reveals a number of strange phenomena. Furthermore, existence depends on observation. Electrons move around the nucleus of an atom. In other words, location and quantity of motion cannot be measured simultaneously.