Question

How many electrons or protons are found in

Answer 1

a) $6.25\cdot 10^{18}$ protons

b) $6.25\cdot 10^{18}$ electrons

c) 1 electron

Explanation:

a)

In this problem, the electric charge that we have is:

$Q=+1 C$

First of all, we observe that this charge is positive: this means that it will consist of protons.

In fact, protons are positively charged particles that reside in the nuclei of the atoms. The charge of one proton is

$q_p = +1.6\cdot 10^{-19}C$

which is also known as fundamental charge.

Therefore, we can write the charge Q as consisting of the charge of several protons:

$Q=N q_p$

where N is the number of protons.

And solving for N,

$N=\frac{Q}{q_p}=\frac{+1}{+1.6\cdot 10^{-19}}=6.25\cdot 10^{18}$

b)

Here the total charge is

$Q=-1C$

The total charge here is negative: this means that it consists of electrons. Electrons are negatively charged particles that orbit around the nucleus in an atom; the charge of one electron is

$q_e = -1.6\cdot 10^{-19}C$

So, its charge is opposite to that of the proton.

Therefore, we can write the charge Q as the sum of the charges of N electrons:

$Q=Nq_e$

Where N is the number of electrons.

And solving for N, we find:

$N=\frac{Q}{q_e}=\frac{-1}{-1.6\cdot 10^{-19}}=6.25\cdot 10^{18}$

c)

In this case, the total net charge is

$Q=-1.6\cdot 10^{-19} C$

As in part b), we notice that the total charge is negative. Therefore, it will consist of N electrons (negatively charged particles), such that we have

$Q=Nq_e$

where

$q_e = -1.6\cdot 10^{-19}C$ is the charge of one electron

N is the number of electrons

And solving for N, we find:

$N=\frac{Q}{q_e}=\frac{-1.6\cdot 10^{-19}}{-1.6\cdot 10^{-19}}=1$

So, 1 electron.