The statement is partially true. While it is true that the K²⁺ ion is isoelectronic with chlorine, it's not the main reason why it doesn't form commonly.

Here's a breakdown:

* Isoelectronic: K²⁺ and Cl^- have the same number of electrons (18). This can indicate some similarity in electronic structure and size.

* Ionization Energy: The second ionization energy of potassium (to remove the second electron) is extremely high. This means it requires a large amount of energy to form K²⁺, making it energetically unfavorable.

* Electronegativity: Potassium is a highly electropositive element, meaning it readily loses one electron to form K⁺. This is the most stable ionic state for potassium due to its electronic configuration.

In conclusion: While the isoelectronic relationship with chlorine might provide some theoretical basis for the existence of K²⁺, the high second ionization energy and potassium's tendency to lose only one electron make the formation of K²⁺ extremely unlikely.