When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Endothermic process - Wikipedia

    en.wikipedia.org/wiki/Endothermic_process

    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]

  3. Freezing - Wikipedia

    en.wikipedia.org/wiki/Freezing

    Freezing is almost always an exothermic process, meaning that as liquid changes into solid, heat and pressure are released. This is often seen as counter-intuitive, since the temperature of the material does not rise during freezing, except if the liquid were supercooled. But this can be understood since heat must be continually removed from ...

  4. Thermal decomposition - Wikipedia

    en.wikipedia.org/wiki/Thermal_decomposition

    The reaction is usually endothermic as heat is required to break chemical bonds in the compound undergoing decomposition. If decomposition is sufficiently exothermic, a positive feedback loop is created producing thermal runaway and possibly an explosion or other chemical reaction. Thermal decomposition is a chemical reaction where heat is a ...

  5. Nucleation - Wikipedia

    en.wikipedia.org/wiki/Nucleation

    Nucleation is a common mechanism which generates first-order phase transitions, and it is the start of the process of forming a new thermodynamic phase. In contrast, new phases at continuous phase transitions start to form immediately. Nucleation is often very sensitive to impurities in the system. These impurities may be too small to be seen ...

  6. Thermochemistry - Wikipedia

    en.wikipedia.org/wiki/Thermochemistry

    Endothermic reactions absorb heat, while exothermic reactions release heat. Thermochemistry coalesces the concepts of thermodynamics with the concept of energy in the form of chemical bonds. The subject commonly includes calculations of such quantities as heat capacity, heat of combustion, heat of formation, enthalpy, entropy, and free energy.

  7. Chemical decomposition - Wikipedia

    en.wikipedia.org/wiki/Chemical_decomposition

    Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity (normal molecule, reaction intermediate, etc.) into two or more fragments. [1] Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. In short, the chemical reaction in which two or more ...

  8. What is graupel? How it is different from sleet or hail? - AOL

    www.aol.com/weather/difference-between-freezing...

    The snowflakes form as air rises, cools, and condenses, usually around an area of low pressure. ... Sleet and freezing rain occur by a similar process, but are different forms of precipitation ...

  9. Thermochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Thermochemical_cycle

    endothermic reactions are chosen with positive entropy changes in order to be favored when the temperature increases, and the opposite for the exothermic reactions. maximal heat-to-work efficiency is the one of a Carnot heat engine with the same process conditions, i.e. a hot heat source at T H and a cold one at T°,