Final answer:
A polarized neuron has a resting membrane potential of approximately -70 mV with the inside being more negatively charged than the outside. This state is maintained by the selective permeability of the ion channels and the active transport of ions across the cell membrane.
Step-by-step explanation:
The polarized state of a neuron refers to the condition where there is a difference in electrical charge across the neuron's cell membrane, resulting in a resting membrane potential. In the polarized state, the inside of the neuron is approximately -70 mV compared to the outside. Because the neuron's membrane is only about 8 nm thick, the resulting electric field is quite significant, around 11 MV/m. This polarization is due to the selective permeability of the membrane and the distribution of ions such as Na+ and K+.
The separation of charge creates a potential difference of about 70 to 90 mV. This electrical state is maintained by the sodium-potassium pump, which uses a significant amount of ATP to transport ions across the cell membrane, contributing to the polarization. When a neuron moves out of this resting state due to a stimulus, a process called depolarization occurs, which is necessary for the initiation of an action potential, the neuron's way of transmitting signals.