ioonimisenergia

Ionization energy refers to the minimum energy required to remove an electron from a neutral atom or molecule in its gaseous state. This process results in the formation of a positive ion, also known as a cation. The electron that is removed is typically the one most loosely held by the atom. The value of ionization energy is a fundamental property of an element and is a key indicator of its chemical behavior.

Ionization energies are typically measured in units of electron volts (eV) or kilojoules per mole (kJ/mol). The first ionization energy is the energy required to remove the first electron, the second ionization energy is the energy to remove the second electron from the now singly charged ion, and so on. Successive ionization energies generally increase significantly because it becomes harder to remove an electron from an increasingly positive species.

Several factors influence ionization energy. Atomic size plays a major role; smaller atoms tend to have higher ionization energies because the nucleus's pull on the electrons is stronger. Nuclear charge is also important; a higher number of protons in the nucleus leads to a stronger attraction for electrons, thus increasing ionization energy. Electron shielding, where inner electrons reduce the effective nuclear charge felt by outer electrons, also affects ionization energy. Furthermore, the stability of electron configurations, such as filled or half-filled subshells, can lead to anomalies in ionization energy trends.