When the neuron generates an action potential, the sodium ions are which of the following? in equal amounts inside and outside in greater amounts outside the neuron than inside in greater amounts inside the neuron than outside not present outside not present inside

The correct answer is **in greater amounts outside the neuron than inside**.<br /><br />Here's why:<br /><br />* **Resting Potential:** When a neuron is at rest (not firing an action potential), it maintains a negative membrane potential. This means the inside of the neuron is more negative compared to the outside. This difference in charge is maintained in part by the sodium-potassium pump, which actively transports sodium ions (Na+) *out* of the neuron and potassium ions (K+) *into* the neuron. This creates a higher concentration of Na+ outside the cell and a higher concentration of K+ inside the cell.<br /><br />* **Action Potential:** When a neuron is stimulated, sodium ion channels in the cell membrane open. Because there's a higher concentration of Na+ outside the cell, these ions rush *into* the neuron, driven by both the concentration gradient (more Na+ outside) and the electrical gradient (the inside of the neuron is negatively charged). This influx of positive sodium ions causes depolarization, the rapid shift in membrane potential that constitutes the action potential.<br />