Final answer:
When voltage gated Na+ channels open and the membrane potential becomes less negative, Na+ ions move into the cell, causing depolarization and a decrease in the charge difference across the membrane.
Step-by-step explanation:
When the voltage gated Na+ channels open and the membrane potential becomes less negative, Na+ ions will move across the membrane into the cell. This movement of positive ions into the cell will depolarize the membrane potential, bringing it closer to zero. The concentration of Na+ ions will increase inside the cell, while the charge difference across the membrane will decrease.