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  2. Fire triangle - Wikipedia

    en.wikipedia.org/wiki/Fire_triangle

    The fire triangle or combustion triangle is a simple model for understanding the necessary ingredients for most fires. [1] The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen). [2] A fire naturally occurs when the elements are present and combined in the right mixture. [3]

  3. Rocket propellant - Wikipedia

    en.wikipedia.org/wiki/Rocket_propellant

    Molecules store thermal energy in rotation, vibration, and translation, of which only the latter can easily be used to add energy to the rocket stage. Molecules with fewer atoms (like CO and H 2) have fewer available vibrational and rotational modes than molecules with more atoms (like CO 2 and H 2 O). Consequently, smaller molecules store less ...

  4. List of states of matter - Wikipedia

    en.wikipedia.org/wiki/List_of_states_of_matter

    Time crystals: A state of matter where an object can have movement even at its lowest energy state. Hidden states of matter: Phases that are unattainable or do not exist in thermal equilibrium, but can be induced e.g. by photoexcitation. Microphase separation: Constituent units forming diverse phases while also keeping united.

  5. Molecule - Wikipedia

    en.wikipedia.org/wiki/Molecule

    The study of molecules by molecular physics and theoretical chemistry is largely based on quantum mechanics and is essential for the understanding of the chemical bond. The simplest of molecules is the hydrogen molecule-ion, H 2 +, and the simplest of all the chemical bonds is the one-electron bond.

  6. Activation energy - Wikipedia

    en.wikipedia.org/wiki/Activation_energy

    In the Arrhenius model of reaction rates, activation energy is the minimum amount of energy that must be available to reactants for a chemical reaction to occur. [1] The activation energy ( E a ) of a reaction is measured in kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). [ 2 ]

  7. Pyrophoricity - Wikipedia

    en.wikipedia.org/wiki/Pyrophoricity

    The creation of sparks from metals is based on the pyrophoricity of small metal particles, and pyrophoric alloys are made for this purpose. [2] Practical applications include the sparking mechanisms in lighters and various toys, using ferrocerium; starting fires without matches, using a firesteel; the flintlock mechanism in firearms; and spark testing ferrous metals.

  8. Chemical energy - Wikipedia

    en.wikipedia.org/wiki/Chemical_energy

    Chemical energy is the energy of chemical substances that is released when the substances undergo a chemical reaction and transform into other substances. Some examples of storage media of chemical energy include batteries, [1] food, and gasoline (as well as oxygen gas, which is of high chemical energy due to its relatively weak double bond [2] and indispensable for chemical-energy release in ...

  9. Molecular spring - Wikipedia

    en.wikipedia.org/wiki/Molecular_spring

    The amount of energy storable in molecular spring is limited by the value of deformation the molecule can withstand until it undergoes chemical change. Manufacturing of such macroscopic device is however out of reach of contemporary technology, because of difficulties of synthesis and molecular arrangement of such long polymer molecules.