How many coulombs of charge enter a 1.20 cm length of the axon during this process?

During the inflow part of a cycle in the neurons approximately 5.6 * 10∧11 Na ions per meter, each with a charge of + e enter the axon.

Therefore, ions will be (5.6 * 10∧11) * (1.2/100)

= 6.72 * 10 ∧8 Na ions

Charge of an electron is 1.6 * 10∧-19 Coulombs

Thus; 6.72 * 10∧ 8 * 1.6 * 10∧-19 = 1.0752 * 10∧-10 coulombs