Sodium is found to be more useful than potassium because of the following reasons:

⇒ Sodium ions are found primarily in the blood plasma and in the interstitial fluid which surrounds the cells while potassium ions are present within the cells.

⇒ Sodium ions help in the transmission of nerve signals, in regulating the flow of water across cell membranes and in the transport of sugars and amino acids into the cells.

⇒ Thus, sodium is found to be more useful than potassium.