During the resting state of neuron, the axoplasm inside the axon contains high concentration of      (I)      ions and low concentration of      (II)       ions.

	I	II
1.	${\mathrm{K}}^{+}$	${\mathrm{Na}}^{+}$
2.	${\mathrm{Na}}^{+}$	${\mathrm{K}}^{+}$
3.	${\mathrm{Mg}}^{++}$	${\mathrm{Cl}}^{-}$
4.	${\mathrm{CO}}_3^{-}$	${\mathrm{Ca}}^{+4}$

During the resting state of a neuron, there is a high concentration of K⁺ (potassium ions) inside the axoplasm (the cytoplasm of the axon) and a low concentration of Na⁺ (sodium ions) inside the axoplasm. This concentration gradient is maintained by the sodium-potassium pump, which actively transports sodium ions out of the cell and potassium ions into the cell, against their respective concentration gradients. This creates an electrochemical gradient, with the inside of the neuron being negatively charged relative to the outside, due to the presence of large negatively charged molecules and the selective permeability of the cell membrane to ions. This resting membrane potential is typically around -70 millivolts.