Final answer:
An ion's size is determined by its charge and electrons. Cations are smaller than their neutral atoms, while anions are larger. Therefore, the chloride ion Cl- has a larger ionic radius than the calcium ion Ca2+.
Step-by-step explanation:
The ionic radius is a measure used to describe the size of an ion. When comparing the ionic radii of a cation and an anion, it is essential to note that a cation, which is positively charged due to the loss of electrons, is always smaller than the neutral atom it is derived from. On the other hand, an anion, which is negatively charged due to the gain of electrons, is always larger than the neutral atom it originates from.
In the case of the ions Ca2+ and Cl-, the calcium ion Ca2+ has lost two electrons, which results in stronger electrostatic attraction between the remaining electrons and the nucleus, effectively reducing its size. Conversely, the chloride ion Cl- has gained an electron, resulting in increased electron-electron repulsion and an effective nuclear charge that is more spread out, thereby increasing its radius. Thus, Ca2+ has a smaller ionic radius compared to Cl-.
The correct answer to the question, 'Which ion has the larger ionic radius: Ca2+ or Cl-?' is B) Cl-.