Our planet Earth has a charge (-5.7 * 10 ^ 5) C. What mass of electrons creates such a charge?

Given:

Q = -5.7 * 10 ^ 5 C – the total charge of the Earth;

q = -1.6 * 10 ^ -19 C – the charge of one electron;

m = 9.1 * 10 ^ -31 kg is the mass of one electron.

It is required to find the total mass of electrons M (kg).

The total number of electrons is found by the formula: n = Q / q;

We find the total mass of electrons by the formula: M = n * m = Q * m / q =

= -5.7 * 10 ^ 5 * 9.1 * 10 ^ -31 / -1.6 * 10 ^ -19 = 32.4 * 10 ^ 5 * 10 ^ -31 * 10 ^ 19 = 3.2 * 10 ^ -6 kg.

Answer: The total mass of electrons is 3.2 * 10 ^ -6 kilograms (or 3.2 milligrams).