Editing Exothermic process (section)

===Endothermic===
In an [[Endothermic process|endothermic reaction]] or system, energy is taken from the surroundings in the course of the reaction, usually driven by a favorable [[entropy]] increase in the system.<ref>{{Cite book |last=Oxtoby |first=David W. |title=Principles of modern chemistry |last2=Gillis |first2=H. P. |last3=Butler |first3=Laurie J. |date=2016 |publisher=Cengage Learning |isbn=978-1-305-07911-3 |edition=8 |location=Andover |pages=617}}</ref> An example of an endothermic reaction is a first aid cold pack, in which the reaction of two chemicals, or dissolving of one in another, requires calories from the surroundings, and the reaction cools the pouch and surroundings by absorbing heat from them.<ref>{{Cite web |date=2020-06-01 |title=The Cold Pack: A Chilly Example of an Endothermic Reaction - Let's Talk Science |url=https://letstalkscience.ca/educational-resources/stem-in-context/cold-pack-a-chilly-example-endothermic-reaction |access-date=2024-06-26 |website=letstalkscience.ca |language=en}}</ref>

[[Photosynthesis]], the process that allows plants to convert carbon dioxide and water to sugar and oxygen, is an endothermic process: plants absorb [[radiant energy]] from the sun and use it in an endothermic, otherwise non-spontaneous process. The chemical energy stored can be freed by the inverse (spontaneous) process: combustion of sugar, which gives carbon dioxide, water and heat (radiant energy).<ref>{{Cite web |title=Photosynthesis - What happens during photosynthesis? - OCR 21st Century - GCSE Combined Science Revision - OCR 21st Century |url=https://www.bbc.co.uk/bitesize/guides/z9pjrwx/revision/1 |access-date=2024-06-26 |website=BBC Bitesize |language=en-GB}}</ref>