What type of ions are present in high concentration inside the axon...

The electrical potential difference across the resting plasma membrane is called as the resting potential. The outer surface of the axonal membrane possesses a positive charge while its inner surface becomes negatively charged. Neurons are excitable cells because their membranes are in a polarised state, meaning the electrical potential difference across the membrane is maintained by ionic gradients.The outer surface of the axonal membrane possesses a positive charge while its inner surface becomes negatively charged and therefore is polarised The sodium-potassium pump transports 3 Na⁺ ions outwards for 2 K⁺ ions into the cell.