which is defined as the energy required to remove an electron from an atom of an element in the gaseous state?
The energy needed to remove one or more electrons from a neutral atom to form a positively charged ion is a physical property that influences the chemical behavior of the atom. By definition, the first ionization energy of an element is the energy needed to remove the outermost, or highest energy, electron from a neutral atom in the gas phase. The process by which the first ionization energy of hydrogen is measured would be represented by the following equation.