20 electrons were attached to a metal ball having a charge of -5e. What is the ball’s charge equal to?

Given:

q1 = -5 * e is the charge of the metal ball;

n = 20 – the number of electrons that are attached to the metal ball;

e = 1.6 * 10 ^ -19 Coulomb – electron charge.

It is required to determine the charge of a metal ball q (Coulomb) after electrons are attached to it.

The ball has a charge:

q1 = – 5 * e = -5 * 1.6 * 10 ^ -19 = -8 * 10 ^ -19;

Attached electrons have a charge:

q2 = -n * e = -20 * 1.6 * 10 ^ -19 = -32 * 10 ^ -19.

The total charge of the metal ball will be equal to:

q = q1 + q2 = -8 * 10 ^ -19 + -32 * 10 ^ -19 = -40 * 10 ^ -19 Coulomb (25e).

Answer: the ball’s charge is -40 * 10 ^ -19 Pendant (25e).