Neurons are able to keep the inside negatively charged and the outside positively charged because:there are more sodium ions outside than inside the neuronthe membrane of the neuron is nearly impermeable to sodium ions.the sodium-potassium pump uses ATP to pump sodium ions out of the neuron.All of these choices are correct.
The neuron is capable of maintaining its inside negatively charged because of the joint action of all the factors mentioned above, which also helps to change this state to allow the nervous impulse.
