Explain why the resting membrane potential of a neuron is negative.

At rest, potassium (K+) ions can move across the cell membrane easily.

At rest, chloride (Cl-) and sodium (Na+) ions cannot move across the membrane easily.

Negatively charged protein molecules that are inside the neuron cannot cross the membrane.

The total difference in voltage between the inside and outside of the cell at rest is negative.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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