Nerve impulse initiates with the movements of

What is action potential?

When a neuron is in resting state,$i.e.$,not conducting any impulse,the axonal membrane is

During the conduction of a nerve impulse along a nerve fiber,what is the sequence of electrical charges on the inner surface of the plasma membrane?

Give scientific reasons:
$(1)$ In an excited nerve fibre region,a positive charge is created inside the plasma membrane.
$(2)$ In some animals,the conduction of nerve impulses is saltatory.

When a neuron is in a resting state,i.e.,not conducting any impulse,the axonal membrane is: