An axon is the relatively

Question

long tail-like part of a neuron, or nerve cell. The outer surface of the axon membrane is charged
positively, and the inner surface is charged negatively. The membrane itself has a dielectric
constant k ~ 5 and a thickness d ~ 10−8 m. Thus the membrane is a kind of capacitor. Assuming
that the membrane acts like a parallel plate capacitor with a plate area of 5 × 10−6 m2, what is
its capacitance?

Answer 1

C = k*A*(epsilono)/d)

The permittivity constant, "epsilon zero" is
8.85*10^-12 Farads/meter

Answer 2

5(8.85*10^-12)*(5*10^-6)/(1*10^-8)
C=2.2125*10^-8C2/Nm