Sodium ions are present in relatively small concentrations compared to other extracellular cations true or false

The answer is false.

Within the extracellular fluid (ECF), the major cation is sodium (Na⁺) while the major cation in the intracellular fluid is potassium (K⁺). Sodium-potassium pump, is a solute pump that pumps three sodium ions out of the cell in exchange for two potassium ions pumped in the cell, both against their concentration gradients. These electrolytes play an important role in maintaining homeostasis. The ECF, in particular the interstitial fluid, is surrounding all of the cells in the body and therefore is crucial for their normal functions. The ECF is maintained by a number of homeostatic mechanisms including regulation of sodium concentration.

Potassium, calcium (Ca²⁺) and magnesium (Mg²⁺)

are cations that are present in relatively small concentrations in ECF.