The answer is repolarization. In the first phases of an action potential,
Sodium ions flow into the cell, through the voltage-gated ion channels, causing depolarization from the resting potential of -70 mV. In the later stages of the action potential, the potassium ion selective filter channels open and potassium ions move from inside of the cell to the outside. This repolarizes the cell before sodium ions begin to be pumped out of the cell.
There are two types of population growth: exponetial growth and logistic growth
A mixture consists of two or more substances which may be elements, compounds or both mixed together physically in any proportion, but not chemically combined. However, a compound consists of two or more elements that are chemically combined in a fixed proportion. Hence, a compound is different from a mixture.