Endothermic vs Exothermic: Hot and Cold Reactions Explained

Endothermic reactions absorb energy, usually as heat, from their surroundings.
Exothermic reactions release energy, often producing heat, light, or sound.
Photosynthesis is endothermic, storing sunlight’s energy in chemical bonds.
Combustion is exothermic, releasing large amounts of heat and light.
Cold packs use endothermic reactions to absorb heat and reduce swelling.
Fireworks display exothermic reactions that dazzle with color and sound.
In endothermic changes, temperature around the reaction often drops.
In exothermic changes, temperature around the reaction often rises.
Both types obey the law of energy conservation—energy isn’t lost, only transferred.
Knowing the difference helps in industries from cooking to power generation.