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An endothermic process may be a chemical process, such as dissolving ammonium nitrate (NH 4 NO 3) in water (H 2 O), or a physical process, such as the melting of ice cubes. [5] The opposite of an endothermic process is an exothermic process, one that releases or "gives out" energy, usually in the form of heat and sometimes as electrical energy. [1]
An endotherm (from Greek ἔνδον endon "within" and θέρμη thermē "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily functions instead of relying almost purely on ambient heat.
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 ...
A eurytherm is an organism, often an endotherm, that can function at a wide range of ambient temperatures. [1] To be considered a eurytherm, all stages of an organism's life cycle must be considered, including juvenile and larval stages. [2]
As an example in everyday life, hand warmers make use of the oxidation of iron to achieve an exothermic reaction: 4Fe + 3O 2 → 2Fe 2 O 3 Δ H ⚬ = - 1648 kJ/mol A particularly important class of exothermic reactions is combustion of a hydrocarbon fuel, e.g. the burning of natural gas:
Vasomotor responses allow control of the flow of blood between the periphery and the core to control heat loss from the surface of the body. Lastly, the organism can show insulation adjustments; a common example being "goosebumps" in humans where hair follicles are raised by pilomotor muscles, also shown in animals' pelage and plumage. [4]
A classical example is the decomposition of mercuric oxide to give oxygen and mercury metal. The reaction was used by Joseph Priestley to prepare samples of gaseous oxygen for the first time. When water is heated to well over 2,000 °C (2,270 K; 3,630 °F), a small percentage of it will decompose into OH, monatomic oxygen, monatomic hydrogen, O ...
Comparison of phase diagrams of carbon dioxide (red) and water (blue) showing the carbon dioxide sublimation point (middle-left) at 1 atmosphere. As dry ice is heated, it crosses this point along the bold horizontal line from the solid phase directly into the gaseous phase. Water, on the other hand, passes through a liquid phase at 1 atmosphere.