Ionization Energy, or Ionisation Energy, and Electronic Configuration Chemistry Tutorial
- Ionisation energy is also referred to as ionization energy.
- Electron configuration is also referred to as electronic configuration.
- Ionization energy, or ionisation energy, is the energy required to remove an electron from a gaseous atom or ion.
- First ionization energy is the energy required to remove one electron from the gaseous atom
First Ionization for Hydrogen: H(g) → H+(g) + e-
First Ionization for Carbon: C(g) → C+(g) + e-
- Ionization energy is measured in kilojoules per mole (kJ mol-1) or electronvolts per atom (eV).
1 eV = 1.602 × 10-19 J
- Ionization energy is given a number of symbols including I and I.E.
The first ionization energy of an atom would therefore be given the symbol I1 or I.E1
- The greater the value of the ionization energy, the harder it is to remove an electron from the gaseous species.
The lower the value of the ionization energy, the easier it is to remove an electron from the gaseous species.
- Ionization energy depends on :
- The charge on the nucleus:
ionization energy increases with increasing numbers of protons in the nucleus, that is, with increasing positive nuclear charge.
(The number of protons in the nucleus of an atom = the atomic number of the element (Z))
- The distance of the electron from the nucleus:
ionization energy decreases as the distance between the electron and the nucleus increases.
- Repulsion between electrons :
ionization energy decreases if 2 negatively charged electrons are in close proximity to each other.
- Ionization energy of atoms provides evidence for the electronic configuration of the atoms.