A negatively charged balloon has 4.5 µC of

To find the number of excess electrons on the balloon, we need to know the charge of a single electron. This is given by the elementary charge, which is approximately 1.6 x 10^-19 Coulombs (C).

Now, we can use the equation Q = ne, where Q is the total charge in Coulombs, n is the number of excess electrons, and e is the elementary charge.

Given that the balloon has a charge of 4.5 µC, which is equivalent to 4.5 x 10^-6 C, we can set up the equation as follows:

4.5 x 10^-6 C = n * 1.6 x 10^-19 C

To solve for n, we can isolate it by dividing both sides of the equation by 1.6 x 10^-19 C.

n = (4.5 x 10^-6 C) / (1.6 x 10^-19 C)

Evaluating this expression, we find:

n ≈ 2.8125 x 10^13 electrons

Therefore, the balloon has approximately 2.8125 x 10^13 excess electrons.