Question

which of the following has the smallest size (a) Na (b) Na+ (c) Na- (d) Cl+​

Answer 1

Among the given species, Cl⁺ has the smallest size.

• As we move across the period, the value of the atomic radii of atoms decreases, hence the size of the atom becomes smaller.
• Since cations are smaller than the size of the atoms and anions are larger than the atoms, Na⁺ will be smaller than Na while Na⁻ will be larger compared to Na. Similarly, Cl⁺ will be very small.
• So, Cl⁺ will be the smallest ion among the given species.