Question

Find the neutral atom in the periodic table which has the same number of electrons as K⁺ and Cl⁻. What is this number?

Answer 1

Argon is a neutral atom in the periodic table and has the same number of electrons as K⁺ and Cl^-. The atomic number of argon is 18. It has 18 electrons. Potassium (K) has 19 electrons but because it loses one electron, it becomes K⁺ and has 18 electrons. On the other hand, chlorine (Cl)  has 17 electrons but because it gains one electron, it forms Cl^- and has 18 electrons.