Final answer:
In the resting potential state of a neuron, there are more sodium ions outside than inside due to the activity of the sodium-potassium pump and differences in membrane permeability.
Step-by-step explanation:
When a neuron is in the resting potential state, there are more sodium ions (Na+) outside the cell than inside. During this state, the sodium-potassium pump uses ATP to actively transport sodium ions out of the neuron and potassium ions (K+) into it. This action, along with the differential permeability of the neuron's membrane to Na+ and K+, establishes an electrical gradient across the cell membrane.
The concentration of Na+ outside the neuron is typically 10 times greater than that inside, creating a strong concentration gradient. Resting membrane potential is maintained around -70 mV, where the interior of the neuron is negatively charged relative to the outside. This polarity is crucial for the neuron's ability to later generate action potentials.