Wave-particle duality

In physics and chemistry, wave–particle duality is the concept that all matter exhibits both wave-like and particle-like properties. A central concept of quantum mechanics, duality addresses the inadequacy of classical concepts like "particle" and "wave" in fully describing the behaviour of objects. Various interpretations of quantum mechanics attempt to explain this ostensible paradox.
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Noun
1. (physics) the property of matter and electromagnetic radiation that is characterized by the fact that some properties can be explained best by wave theory and others by particle theory
(synonym) duality
(hypernym) property
(classification) physics, physical science, natural philosophy

A fundamental concept of of quantum theory. It states that waves can behave like particles and particles can behave like waves. For example photons are the particles of zero mass associated with waves of electromagnetic radiation. Electromagnetic radiation can be thought of as either a wave or a particle but never as both at the same time. Thinking of electrons as waves can lead to an understanding of why they exist in only specific orbits around atomic nuclei.

The observation that electrons, photons and other very small entities behave like particles in some experiments and like waves in others.Compare with quantum .