First Ionization Energy

Definition

The first ionization energy is the amount of energy required to remove the outermost electron from an atom in its gaseous state.

Related terms

Atomic Radius:

The distance from the center of an atom's nucleus to its outermost electron.

Electronegativity:

A measure of an atom's ability to attract electrons towards itself in a chemical bond.

Shielding Effect: The reduction in attraction between an electron and the nucleus due to the presence of other electrons.