Find the net charge of a system consisting of 6.25×10^6 electrons and 7.75×10^6 protons. express your answer using three significant figures.

2.40 x 10⁻¹³ C

Explanation:

= number of electrons = 6.25 x 10⁶

= charge on electron = - 1.6 x 10⁻¹⁹ C

= number of protons = 7.75 x 10⁶

= charge on proton =  1.6 x 10⁻¹⁹ C

Net charge is given as

Q = +

Q = (- 1.6 x 10⁻¹⁹) (6.25 x 10⁶) + (1.6 x 10⁻¹⁹) (7.75 x 10⁶)

Q = 2.40 x 10⁻¹³ C

+15-35=-20

going in opposite directions