When a nerve cell fires, a charge is transferred across the cell membrane to change the cell's potential from negative to positive. For a typical nerve cell, 9.0 pC of charge flows in a time of 0.47 ms.
What is the average current through the cell membrane?

Explanation:

The given data is as follows.

      q = 9.0 pC =    (as 1 pC = )

      t = 0.47 ms =  (as 1 ms = )

As we know that relation between charge and current is as follows.

             I =

Putting the given values into the above formula as follows.

             I =

               =

               =

or,           = 19.14 nA

Thus, we can conclude that the average current through the cell membrane is 19.14 nA.