91Ó°ÊÓ

An electric charge is an entity or a property of a particle that causes it to get influenced via experiencing a force when placed inside an electric or magnetic field.The charge due to electrons is mainly what is referred to as electric charge and one electron carries a charge of $1.6×{10}^{-19}\mathrm{C}$. Like charges repel each other and unlike charges attract each other.

There is a finite charge carried by each ion when it enters the axon.

The total charge is calculated as,

$\mathrm{Q}=\mathrm{Ne}$ ….. (1)

Where N is the number of ions and e is the electric charge having the value.$1.6×{10}^{-19}\mathrm{C}$

Calculate N by the given values,

$$\begin{gathered} \mathrm{N}=(\mathrm{no}.\mathrm{ofions}/\mathrm{length})(1.5\mathrm{cm}) \\ =\left(5.6×{10}^{11}\mathrm{ions}/\mathrm{m}\right)\left(1.5×{10}^{−2}\mathrm{m}\right) \\ =8.4×{10}^9\mathrm{ions} \end{gathered}$$

Thus, the total charge according to equation (1) is,

$$\begin{gathered} \mathrm{Q}={\mathrm{N}}_{\mathrm{e}} \\ =\left(8.4×{10}^9\right)\left(1.6×{10}^{−19}\mathrm{C}\right) \\ =1.3×{10}^{−9}\mathrm{C} \\ =1.3\mathrm{nC} \end{gathered}$$

Hence, the magnitude of charge entering the axon is 1.3 nC .