The bonding atomic radius (covalent radius) is half the distance between the nuclei of two identical atoms joined by a covalent bond. It provides a consistent way to assign sizes to atoms for comparison. For example, the covalent radius of chlorine is found from half the internuclear distance in the Cl₂ molecule.

成键原子半径(共价半径)是由共价键相连的两个相同原子核间距离的一半。它提供了一种为原子赋予可供比较的尺寸的一致方法。例如,氯的共价半径由 Cl₂ 分子中核间距离的一半求得。