Ionisation Energies

Ionisation Energies

The process of removing electrons from an atom is called ionisation. The energy needed to remove each successive atom is called the first, second, third, etc., ionisation energy. 

The process of the first ionisation energy (also known as I.E.) of an element is summarised in the equation:

X(g) → X⁺(g) + e^-

To complete the equation, simply put in the atom accordingly.

Key Terms

The molar first ionisation energy of an element is the energy required to remove one mole of electrons from one mole of its gaseous atoms.

Electron shielding/screening is the repulsion between electrons in different shells. Inner shell electrons repel outer shell electrons.

Electrons are held in their shells by the attraction to the positive nucleus. The greater the attraction, the greater the ionisation energy. The attraction depends on there factors:

• The size of the nuclear charge - greater the nuclear charge…