Which noble gas has the same electron arrangement as each of the following ions?

Question

K +

Mg 2+

S 2-

Answer 1

K⁺ is potassium that has lost 1 electron. Argon is isoelectronic

Mg²⁺ is magnesium that’s lost 2 electrons. Neon is isoelectronic

S^2-is sulfur with 2 extra electrons. Argon is isoelectronic