Question

What ion is isoelectronic with Ar?

Answer 1

The ions that are isoelectronic with Argon (Ar) include K+, Cl-, and S²-, which all have 18 electrons but differ in their nuclear charges.

Step-by-step explanation:

The ion that is isoelectronic with Argon (Ar) can be from the isoelectronic series P³-, S²-, Cl-, Ar, K+, Ca²+, and Sc³+ which all share the [Ne]3s²3p6 electron configuration. Specifically, K+, Cl-, and S²- are examples of ions that are isoelectronic with Ar, as they all have 18 electrons, the same number as Ar. However, the size of these isoelectronic ions varies due to the different nuclear charges, with the radius of the ions decreasing as the nuclear charge increases.

Answer 2

An ion that is isoelectronic with Ar has the same electron configuration, [Ne]3s²3p⁶. Ions such as K+, Cl−, and S2− are isoelectronic with argon as they all have 18 electrons. Their sizes differ due to variations in nuclear charge.

Step-by-step explanation:

Atoms and ions that have the same electron configuration are said to be isoelectronic. If we are looking for an ion that is isoelectronic with argon (Ar), we need to find an ion that has the same electron configuration as Ar, which is [Ne]3s²3p⁶.

Some ions that are isoelectronic with Ar include K+, Cl−, and S2−, all of which have 18 electrons like Ar. The nuclear charge affects the size of these ions; the greater the nuclear charge, the smaller the ion's radius in a series of isoelectronic ions. Therefore, although K+ (Z = 19), Cl− (Z = 17), and S2− (Z = 16) all have the same number of electrons, their sizes vary due to the different numbers of protons.

Thus, some ions that are isoelectronic with Ar are K+, which has one more proton than Ar, Cl−, which has one fewer proton, and S2−, which has two fewer protons.