exothermic
Releases heat outward
Exothermic describes a chemical reaction or process that releases heat into its surroundings.
The opposite is endothermic, which absorbs heat.
Combustion is the classic exothermic reaction—burning fuel releases energy as heat and light.
In chemistry class, students learn to identify exothermic reactions by the warmth they produce: The mixture grew hot to the touch, confirming the reaction was exothermic.
Burning gas made visible
- fireCombustion with flames
- burningCombustion in progress
- oxidationLosing electrons chemically
- ignitionStarting combustion process
blaze · inferno · bonfire · conflagration · incineration · embers · smoldering · charring
Thermodynamic total heat quantity
- calorimetryMeasuring heat in reactions
- spontaneousArising without external cause
- activation energyMinimum energy for transformation
- bond energyStrength of atomic linkage
Heat-fusing metal pieces
- smeltingExtracting metal from ore
- polymerizationMonomers bonding into chains
- vulcanizationChemically strengthening raw rubber
- thermitePyrotechnic metal powder compound
hand warmers · self-heating · curing · epoxy · furnace · kiln · foundry · casting
Transition to firm state
- freezingExtremely cold
- nucleationInitial cluster formation
- crystallizationForming ordered solid structure
- supercoolingLiquid chilled below freezing
precipitation · annealing · phase transition · condensation · deposition · crystal growth · supersaturation
Nuclear breakup releasing energy
- fusionJoining into unity
- uraniumElement ninety-two
- plutoniumActinide, atomic number 94
- radioactive decayUnstable atoms releasing energy
chain reaction · reactor · critical mass · neutron · isotope · half-life · nuclear power · atomic
Cellular nutrient conversion
- cellular respirationCell-level fuel burning
- digestionBodily food breakdown
- fermentationMicrobial sugar conversion
- decompositionBreakdown into simpler parts
ATP · mitochondria · thermogenesis · body heat · composting · aerobic · anaerobic · glycolysis
flame
Burning gas made visible
ignition · blaze · inferno · bonfire · conflagration · incineration · embers · smoldering · charring · pyre
enthalpy
Thermodynamic total heat quantity
- calorimetryMeasuring heat in reactions
- spontaneousArising without external cause
- activation energyMinimum energy for transformation
bond energy · surroundings · joules · kilojoules · isothermal
welding
Heat-fusing metal pieces
- smeltingExtracting metal from ore
- polymerizationMonomers bonding into chains
- vulcanizationChemically strengthening raw rubber
thermite · hand warmers · self-heating · curing · epoxy · furnace · kiln · foundry · casting
solidification
Transition to firm state
- freezingExtremely cold
- nucleationInitial cluster formation
- crystallizationForming ordered solid structure
supercooling · precipitation · annealing · phase transition · condensation · deposition · crystal growth · supersaturation
fission
Nuclear breakup releasing energy
radioactive decay · chain reaction · reactor · critical mass · neutron · isotope · half-life · nuclear power · atomic
metabolism
Cellular nutrient conversion
- cellular respirationCell-level fuel burning
- digestionBodily food breakdown
- fermentationMicrobial sugar conversion
decomposition · ATP · mitochondria · thermogenesis · body heat · composting · aerobic · anaerobic · glycolysis
- energyelectricity, power, oil, fuel, gas
- heatheat transfer, heatwave, radiation, convection, insulators
- "Exo-" wordsexoplanet, exoskeleton, exosuit, exobiology, exosphere
- thermochemistryenthalpy, calorimetry, heat capacity, specific heat, heat of fusion
- thermodynamicsentropy, enthalpy, heat transfer, free energy, heat capacity
- thermal analysisDMA, thermogram, calorimetry, heat flow, melting point
- exothermic reactionProcess releasing thermal energy
thermal, therm, endothermic, thermic, thermochemistry, endotherms