Endothermic — তাপাধিশোষী
An endothermic reaction absorbs heat from its surroundings, so the container feels cooler as it proceeds.
Definition
In an endothermic reaction the products store more energy than the reactants did, so the reaction must pull heat in from its surroundings and the mixture cools — the thermometer reading falls. Photosynthesis, the decomposition of limestone into quicklime and carbon dioxide, and dissolving ammonium salts in water are classic examples; cooking absorbs heat continuously, though it mixes physical with chemical change. Chemists mark these reactions with a positive enthalpy change (ΔH > 0), and most decomposition reactions belong here.
For example
Dissolve a little ammonium chloride in water and hold the glass: it turns refreshingly cool, because the dissolving is pulling heat from your palm.