Endothermic Reactions
Summary: Chemical reactions that absorb energy from the surroundings. Tags: concepts chemistry Created: 2026-05-03T00:00:00Z Last Updated: 2026-05-03T00:00:00Z
Content
Endothermic reactions take in energy (usually heat) from the surroundings, causing the surroundings to feel colder. Energy is required to break bonds in reactants, and in endothermic reactions, more energy is absorbed breaking bonds than is released forming new bonds.
Examples:
- Thermal decomposition (e.g., heating calcium carbonate to form calcium oxide and CO2)
- Photosynthesis (absorbing light energy)
- Dissolving ammonium nitrate in water
Contrast with exothermic reactions, which release energy.