Skip to main content
Back

Endothermic & Exothermic Reactions definitions

Control buttons has been changed to "navigation" mode.
1/15
  • Endothermic Reaction
    Absorbs thermal energy from surroundings, causing molecules to speed up and break bonds, often resulting in phase changes like melting or vaporization.
  • Exothermic Reaction
    Releases thermal energy to surroundings, causing molecules to slow down and form bonds, often resulting in condensation or freezing.
  • Thermal Energy
    Form of energy transferred as heat, influencing molecular motion and phase changes during chemical reactions.
  • Bond Breaking
    Process requiring energy input, leading to separation of atoms within molecules, common in heat-absorbing reactions.
  • Bond Formation
    Process releasing energy as atoms connect to form molecules, typical in heat-releasing reactions.
  • Phase Change
    Transition between solid, liquid, and gas states, driven by energy absorption or release during reactions.
  • Melting
    Transition from solid to liquid as heat is absorbed, also known as fusion in thermochemistry.
  • Vaporization
    Transition from liquid to gas due to energy absorption, breaking molecular connections.
  • Sublimation
    Direct transition from solid to gas, bypassing the liquid phase, requiring significant energy input.
  • Condensation
    Transition from gas to liquid as molecules lose energy and come closer together.
  • Freezing
    Transition from liquid to solid as heat is released and molecular motion decreases.
  • Deposition
    Direct transition from gas to solid, skipping the liquid phase, involving energy release.
  • Energy Diagram
    Graphical representation showing energy changes from reactants to products during a chemical reaction.
  • Enthalpy
    Measure of total energy change in a reaction, indicated by delta H, positive for heat absorption, negative for heat release.
  • Delta H
    Symbol representing enthalpy change; positive for endothermic and negative for exothermic processes.