How do covalent radii change from carbon to lead in Group 14?

In Group 14, the covalent radii of the elements increase as you move down the group from carbon to lead. This trend occurs because each successive element adds a new electron shell outside the core of the atom, effectively increasing the atomic size.12

The following table illustrates the increase in covalent radii (measured in angstroms) for the elements in the carbon group:

| Element | Covalent Radius (Å) |
| :--- | :--- |
| Carbon | 0.76 |
| Silicon | 1.11 |
| Germanium | 1.20 |
| Tin | 1.39 |
| Lead | 1.46 |

This increase in atomic size is a consequence of the additional electronic shells, which provide substantial screening of the larger nuclear charge. As the atoms become larger, the attraction between the nucleus and the outermost valence electrons decreases, which contributes to the observed changes in physical and chemical properties across the group, such as the transition from nonmetallic to metallic character.23