Final answer:
Potassium is more concentrated inside the cell compared to other cations due to the activity of the sodium-potassium pump, which creates a net negative charge inside the cell. Sodium-potassium pumps in the cell membranes help maintain the high levels of potassium and low levels of sodium in the intracellular fluid.
Step-by-step explanation:
Potassium is more concentrated inside the cell compared to other cations because of the activity of the sodium-potassium pump. This pump actively transports three sodium ions out of the cell for every two potassium ions in, creating a net negative charge inside the cell. Additionally, the high levels of potassium and low levels of sodium in the intracellular fluid (ICF) are maintained by sodium-potassium pumps in the cell membranes.