IB Chemistry S3.1.3 Periodicity of Properties Key Definitions

The atomic radius is the distance from the nucleus of an atom to the outermost electron.

Effective nuclear charge is the net positive charge experienced by valence electrons.

Electron affinity (EA) is the energy change when an atom gains an electron. A more negative value indicates a stronger attraction for the electron.

Electronegativity is the ability of an atom to attract shared electrons in a covalent bond.

Ionic radius is the measure of an ion's size, defined as the distance from its nucleus to the outermost electron, influenced by its charge and electron configuration.

Ionization energy ($IE$) is the minimum energy required to remove an electron from a gaseous atom in its ground state.

Isoelectronic ions are ions that have the same number of electrons but different nuclear charges.