Ionization energy The sciences of physics and chemistry use different measures of ionization energy. In physics, the unit is the amount of energy required to remove a single electron from a single atom or molecule, expressed as electronvolts. In chemistry, the unit is the amount of energy required for all of the atoms in a mole of substance to lose one electron each: molar ionization energy or enthalpy, expressed as kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). Comparison of "E" of elements in the periodic table reveals two periodic trends: The latter trend results from the outer electron shell being
Work (physics) "weight "lifted" through a height", which is based on the use of early steam engines to lift buckets of water out of flooded ore mines. According to Dugas, it is to Solomon of Caux "that we owe the term "work" in the sense that it is used in mechanics now". The SI unit of work is the joule (J). The SI unit of work is the joule (J), which is defined as the work expended by a force of one newton through a displacement of one metre. The dimensionally equivalent newton-metre (N⋅m) is sometimes used as the measuring unit for