1) Size of an atom 
metallic radius; covalent radius; atomic radii. Compare with ionic radius. One half the distance between nuclei of atoms of the same element, when the atoms are bound by a single covalent bond or are in a metallic crystal. The radius of atoms obtained from covalent bond lengths is called the covalent radius; the radius from interatomic distances in...
The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the centre of the nucleus to the boundary of the surrounding cloud of electrons. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Three widely used definiti...
half the distance between the nuclei of identical neighbouring atoms. An atom has no rigid spherical boundary, but it may be thought of as a tiny, ... [2 related articles]
Radius of an atom.
Radius of an atom.