---
title: "Wave-Particle Duality — AP Physics 2 Definition & Exam Guide"
description: "Wave-particle duality means light and matter show both wave and particle behavior. Core to AP Physics 2 Unit 7, linking photons, de Broglie wavelength, and interference."
canonical: "https://fiveable.me/ap-physics-2-revised/key-terms/wave-particle-duality"
type: "key-term"
subject: "AP Physics 2"
---

# Wave-Particle Duality — AP Physics 2 Definition & Exam Guide

## Definition

Wave-particle duality is a fundamental concept in quantum physics that suggests particles like electrons and photons exhibit both wave-like and particle-like properties. It means that these entities can behave as both discrete particles and spread-out waves simultaneously.

## Related Study Guides

- [7.5 Properties of Waves and Particles](/ap-physics-2-revised/unit-7/properties-waves-particles/study-guide/gXV2Vd4gN69ociflUUAD)
- [Unit 7 Overview: Quantum, Atomic, and Nuclear Physics](/ap-physics-2-revised/unit-QUWmBhy0eEwkfCSU/review/study-guide/rcA6NJTYu2BTlTMRS2dT)

## Review

### Related Terms

- Quantum mechanics: The branch of physics that deals with phenomena at very small scales, including wave-particle duality.
- Superposition: This term describes how quantum systems can exist in multiple states simultaneously until measured or observed.
- [Interference pattern](/ap-physics-2-revised/key-terms/interference-pattern): When waves overlap and interact constructively or destructively, creating alternating bright and dark regions, forming patterns such as those observed in the double-slit experiment.