The major ion in extracellular compartment
High-Yield Explanation
Ans: b (Na+) Ref: Ganong 22nd ed/ p. 30, 32Most abundant ion in ECF is Na+.ECFMost abundant ion - Na+Most abundant cation - Na+Most abundant anion - Cl-ICF:-Most abundant cation - K+Most abundant anion - PO43- (followed by protein).ECF contains more of Na+, Cl-, HCO3, Ca2+.ICF contains more of K+, PO4, organic anion, protein, magnesium.