Explain covalent radius and ionic radius with examples.

(N/A) Covalent Radius: It is defined as one-half of the distance between the nuclei of two identical atoms bonded by a single covalent bond in a molecule.
Example: The bond length of $Cl-Cl$ in a $Cl_{2}$ molecule is $198 \ pm$. Therefore, the covalent radius of chlorine is $\frac{198}{2} = 99 \ pm$.
Ionic Radius: It is defined as the effective distance from the center of the nucleus of an ion up to which it has an influence on its electron cloud.
Example: In an ionic crystal like $NaCl$, the distance between the nuclei of $Na^{+}$ and $Cl^{-}$ ions is $276 \ pm$. If the ionic radius of $Cl^{-}$ is $181 \ pm$, then the ionic radius of $Na^{+}$ is $276 - 181 = 95 \ pm$.