Answer: 12.8 A
Explanation:
Current is defined as the rate of flow of electric charge based on the formula:
I(current) = deltaQ(change in charge)/deltat(change in time).
First, however, we must convert the number of electrons into the number of coulombs. Based on the fact that the charge of 1 electron or 1 elementary charge is equal to 1.6*10^-19 C, we can calculate:
3.2*10^20 e = 1.6*10^-19*3*10^20 C = 51.2 C.
Now we use: I = Q/t = 51.2/4 = 12.8 A.
Hope this helped.