Oxygen and glucose and energy. <span />
Pure sodium can severely harm your body (toxic) which can lead to death
The refractory period makes the cell rest. In this period, the cell becomes able to depolarize again by collecting ions.
Conductive when liquid - ions are charged particles, but ionic compounds can only conduct electricity if their ions are free to move. So ionic compounds do not conduct electricity when they are solid, but they do conduct electricity when they are dissolved in water or when they are melted.