Suppose a speck of dust in an electrostatic precipitator has 1.0000×10 12 protons in it and has a net charge of −5.00 nC (a very large charge for a small speck). How many electrons does it have? Negative charge of an electron = 1.602 × 10 −19 C 1.0312 × 10^12 e 2.0312 × 10^15 e 2.2312 × 10^12 e 2.0312 × 10^12 e