Question

Which statement is correct among the following: (Considering the hypothetical values)

• A. Radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $C{l}^{+}$ is $1.54\stackrel{o}{A}$
• B. Radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $Na$ is $1.54\stackrel{o}{A}$
• C. Radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $C{l}^{-}$ is $0.81\stackrel{o}{A}$
• D. Radius of $Na$ atom is $0.95\stackrel{o}{A}$ while that of $N{a}^{+}$ is $1.54\stackrel{o}{A}$

Answer 1

The correct option is B Radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $Na$ is $1.54\stackrel{o}{A}$

We know that generally atomic radius decreases along the period as effective nuclear charge increases along the period in periodic table. Again cations are always smaller than their parent atom and oppositely anions are always larger than their parent atom.
So radius of $Cl$ cannot be greater than $C{l}^{+}$ amd smaller than that of $C{l}^{-}$.
So the correct statement here is radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $Na$ is $1.54\stackrel{o}{A}$ as the radius decreases along the period.