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abstraction > mathematical concept > number > quantity > energy

energy
subject			fact

energy	has unit energy unit
	is a kind of quantity
number	has value

Kinds of energy :

• binding energy (2 facts) - The energy required to break up a system. In particular, the binding energy of an atomic nucleus is the energy released in the formation of the nucleus. The most strongly bound nuclei are those with atomic weights between about 50 and 65 (the iron group). Lighter nuclei are less strongly bound because of their larger surface-to-volume ratios; heavier nuclei, because the effects of Coulomb repulsion increase with the nuclear charge.
• energy level (3 facts) - Any of the several discrete states of energy in which an atom or ion can exist. For example, an orbital electron can exist only in those energy levels that correspond to an integral number of deBroglie wavelengths in a Bohr atom., Allowed energy state for electrons orbiting the nucleus of an atom.
• enthalphy (3 facts) (H) - The heat content of a body. H = U + pV, where U is the internal energy, p is the pressure, and V is the volume.
• excitation potential (2 facts) - Amount of energy required to bring an electron from its ground state to a given excited state (measured in electron volts).
• Fermi level (2 facts) - The maximum energy of any particle in a group of low-temperature subatomic particles called fermions. Fermions, such as electrons, cannot occupy the same space at the same energy. Thus, if many fermions are placed close together, their energies must all be different. The energy of that particle with the largest energy is the Fermi energy of the system.
• ground state (2 facts) - The state in which all electrons are in the lowest possible energy states.
• Hartree energy (6 facts) (E_h)
• ionization potential (2 facts) - The minimum energy required to remove an electron from an atom. It always takes a higher energy to remove a second electron from a singly ionized atom, a still higher energy to remove a third, etc. The ionization potential for hydrogen is 13.596 eV, which corresponds to a wavelength of 912 Å.
• kinetic energy (2 facts) - The energy associated with motion; the work that must be done to change a body from a state of rest to a state of motion, equal to 1/2 mv² for a body of mass m moving at velocity v.
• pairing energy (3 facts) (δ) - A quantity which expresses the fact that nuclei with odd numbers of neutrons and protons have less energy and are less stable than those with even numbers of neutrons and protons.
• Planck energy (3 facts) - An energy of 1.22 × 10¹⁹ GeV (billion electron volts), at which the strength of the gravitational interactions of fundamental particles becomes comparable to that of the other interactions. It is believed that the quantum effects of gravity become important at approximately this energy., About 1000 kilowatt hours. The energy necessary to probe to distances as small as the Planck length. The typical energy of a vibrating string in string theory.
• potential energy (1 kind, 4 facts)
• rest-mass energy (2 facts) - The energy which a particle has even when it is at rest. According to the famous relation E = mc² of special relativity, this rest energy is equal to the rest mass of the particle-the mass it has when a rest-times the square of the speed of light. If the mass is in grams and the speed of light in centimeters per second (c = 2.998 × 10¹⁰ centimeters per second), then the energy is given in ergs.
• thermal energy (2 facts) - Energy associated with the motions of the molecules, atoms, or ions in a substance.
• threshold energy (2 facts) - Difference between the energy at the first excited level and that of the ground state.
• vibrational energy (2 facts) - Motion of the pair of nuclei in a diatomic molecule along the direction of the internuclear axis (cf. rotational energy).
• work function (3 facts) (W) - The amount of energy needed to release an electron from the attraction of positive ions in a metal. It is different for different metals.
• zero-point energy (2 facts) - The energy of the lowest state of a quantum system. Amount of vibrational energy allowed by quantum mechanics to be associated with atomic particles at 0 K, whereas classical mechanics requires this to be zero. Also, the energy of an electron in its ground state.