Atomic radius

[805601399]

How would the radius of a compound/molecule with 3 or more atoms in it be calculated?

[Lindsay Beckwith 2B]

The atomic radius involving molecules is usually dependent on the bond type. For covalent bonds between two atoms of the same element, their radii will be 1/2 the distance in between their two nuclei because they equally attract the electrons (thus the bond length is the covalent diameter). For covalent bonds between two different elements, their covalent radii depends on the polarity of the bond/how equally the atoms are shared.

For ionic bonds, we know the atoms are not shared equally between the cation and anion. Thus, to get the radius, you have to have the distance between the two nuclei and divide this number by an atom's atomic size.