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