What is the resting membrane potential and how is it established?

In resting axons, the inside of the cell is more negative than the outside of the cell. This potential difference has a value of -60 to -70mV and is very important in the transmission of impulses. This potential difference is established by both the Na+/K+ pump and leak channels in the cell surface membrane:
The Na+/K+ pump is an ATPase pump which uses the energy released from the hydrolysis of 1 ATP (to ADP + Pi) to pump 2 K+ ions into the cell and 3 Na+ ions out of the cell. As more positive charge leaves the cell than enters, the inside is slightly negative compared to the outside, and an electrochemical gradient is established.There are leak channels for many different ions in the cell surface membrane. There are many more leak channels for K+ than there are for Na+, which means that significantly more K+ diffuses back out of the cell down its concentration gradient than Na+ diffuses back in. This increases and maintains the resting membrane potential.