Written by the Fiveable Content Team • Last updated August 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated August 2025
Definition
Mass-energy equivalence is the concept that mass and energy are interchangeable, as described by Einstein's famous equation E=mc². It states that a small amount of mass can be converted into a large amount of energy, and vice versa.