Question

Give the formulas of two oppositely charged ions which have the same electron configuration as argon.

Answer 1

Answer: $K+$ and $Cl^-$

Explanation: Argon has an atomic number of 18. The electronic configuration is:

Ar: $1s^22s^22p^63s^23p^6$

Potassium [K] has atomic number of 19. This means it has 19 electrons.It lose one electron to give $K^+$

K:$1s^22s^22p^63s^23p^64s^1$

$K^+$: $1s^22s^22p^63s^23p^6$

Chlorine [Cl] has atomic number of 17. This means it has 17 electrons.It gains one electron to give $Cl^-$

Cl:$1s^22s^22p^63s^23p^5$

$Cl^-$: $1s^22s^22p^63s^23p^6$