Cell membrane under resting conditions is impermeable to all the ions except_____________?

Explanation

At rest, the neuronal membrane has many potassium leak channels and is therefore much more permeable to K+ than to Na+ or large intracellular anions. K+ tends to diffuse outward, helping establish the negative resting potential inside the cell. The likely alternative is Na+, because sodium is important during the action potential, but resting permeability to Na+ is relatively low.