Why does Cl- have a larger ionic radius than CA2+ ?

Cl- has a larger ionic radius than Ca2+ due to the difference in their electronic configurations and effective nuclear charges.

An ionic radius refers to the size of an ion. It is determined by the balance between the attraction of the protons in the nucleus and the repulsion between electrons.

In the case of Cl-, it has gained one electron to achieve a stable electron configuration with a complete outermost energy level. This additional electron increases the repulsion between the electrons, causing the electron cloud to expand. As a result, the ionic radius of Cl- is larger than the neutral chlorine atom.

On the other hand, Ca2+ has lost two electrons to achieve a stable electron configuration. The loss of these electrons reduces the electron-electron repulsion in the electron cloud, causing it to contract. Therefore, the ionic radius of Ca2+ is smaller than the neutral calcium atom.

Additionally, the effective nuclear charge, the net positive charge experienced by the valence electrons, also affects the ionic radius. In the case of Cl-, it has 17 protons in its nucleus and 18 electrons, resulting in a net charge of -1. This means that the valence electrons experience a weaker effective nuclear charge, leading to a larger ionic radius.

On the other hand, Ca2+ has 20 protons in its nucleus, but only 18 electrons. This results in a net charge of +2, causing the valence electrons to experience a stronger effective nuclear charge. This stronger pull from the nucleus leads to a smaller ionic radius for Ca2+ compared to neutral calcium.

In summary, the difference in electronic configurations and effective nuclear charges causes Cl- to have a larger ionic radius than Ca2+.

To understand why Cl- has a larger ionic radius than Ca2+, we need to look at the concept of ionic radius.

Ionic radius refers to the size of an ion, specifically the distance between the nucleus of an ion and its outermost electron shell. The ionic radius can be influenced by various factors such as the nuclear charge, the number of electrons, and the energy levels.

In the case of Cl- and Ca2+, Cl- has a larger ionic radius compared to Ca2+ due to the following reasons:

1. Nuclear Charge: Cl- has a greater number of protons in its nucleus compared to Ca2+. Since both ions have the same number of electrons, the stronger nuclear charge in Cl- pulls its electrons closer, resulting in a smaller ionic radius.

2. Electron-Electron Repulsion: In Cl-, the outermost shell contains 7 electrons, while in Ca2+, the outermost shell contains only 2 electrons. This means that Cl- experiences more electron-electron repulsion, which causes the electron cloud to expand, resulting in a larger ionic radius.

3. Effective Nuclear Charge: The effective nuclear charge refers to the net positive charge experienced by an electron in an atom or ion. In Cl-, the effective nuclear charge is less than in Ca2+. The increased charge in Ca2+ pulls the electrons closer, resulting in a smaller ionic radius.

In summary, Cl- has a larger ionic radius than Ca2+ due to its higher nuclear charge, more electron-electron repulsion, and lower effective nuclear charge.