Question

1pt which of the following ions has the smallest ionic radius?

a. c⁴+
b. b³+
c. be²+
d. li+

Explanation:

When comparing ionic radii of isoelectronic ions (ions with the same number of electrons), the ion with the highest nuclear charge (more protons) will have the smallest ionic radius. All these ions (\(C^{4+}\), \(B^{3+}\), \(Be^{2+}\), \(Li^{+}\)) are isoelectronic (they all have 2 electrons). The nuclear charge (number of protons) for \(Li^{+}\) is 3, for \(Be^{2+}\) is 4, for \(B^{3+}\) is 5, and for \(C^{4+}\) is 6. As the nuclear charge increases, the electrons are pulled more strongly towards the nucleus, reducing the ionic radius.

Answer:

A. \(C^{4+}\)