Question

Potassium is a mineral which appears in abundance in all living plant and animal cells. The human body uses it to promote regular heartbeat, help build muscles, help contract muscles, regulate blood pressure, and control the water balance in body tissues and cells. Calcium is a mineral that primarily functions in your body by making your bones and teeth hard. The rest is in your blood and soft tissues; it helps your muscles contract and your blood clot, and helps your nervous system work properly. According to your knowledge of atomic structure, explain why the calcium atom is smaller than potassium atom.

Answer 1

Calcium also shares the same fourth period in the periodic table in which potassium present. The size of the atomic radius decreases from left to right in the period from left to right. Potassium present left to the calcium in the fourth period.

The reason for the decrease in the atomic radius due to the fact though electrons and protons increases but the valence shell remains the same from moving from left to right, therefore, as the net charge increases with the increase in the electrons result in shrinking of the valence shell and resulting in the decrease of the size of the atom.