Force on an electron between two parallel plates

[bsmm11]

Homework Statement

Two parallel plates are separated by 10.0cm and a potential difference of 500.0V is maintained between them. What is the force on an electron between the plates?

Homework Equations

The Attempt at a Solution

E = F / q = kQ / r²
V = kQ / r = Er = Fr / q
F = Vq / r = 500.0 * e / 0.100 = 8 * 10^-16

The actual answer is 8 * 10^-18
Where did my calculation go wrong?

 

[Dadface]

I got the same answer as yourself.Don't forget the units.