Relative Charges of Protons, Neutrons and Electrons

As well as their relative masses, we also need to know what the relative charges of protons, neutrons and electrons are. We will start by looking at the actual charges of the three particles (measured in Coulombs) and then use these to work out the relative charges. You do not need to learn the actual charges, but doing it this way will help you to understand where the relative charges come from and why they are so useful.

The actual charges of protons, neutrons and electrons are as follows:

As you can see, the charge of a neutron is quite easy to deal with (it is just 0C), but the charges of the proton and the electron are very small numbers which it would be easier if we didn’t have to deal with.

Luckily, in chemistry we are mostly interested in how the charges of the different particles compare to each other, rather than what the actual charges are. Therefore, we can use the concept of relative charge to make things much simpler.

Protons and electrons have relative charges of +1 and -1

If you compare the charge of the proton to the charge of the electron you will notice that apart from the positive and negative signs they are both the same number. The only difference is that the charge of the proton is positive and the charge of the electron is negative.

Therefore, we can give the proton a relative charge of +1 and the electron a relative charge of -1. This makes it clear that their charges are positive and negative versions of the same number, without having to worry about what that number actually is.

Neutrons have a relative charge of 0

Since the neutron has an actual charge of 0C (it is neutral), we can simply give it a relative charge of 0. Notice that we drop the units of Coulombs, because relative charge does not have units.

To summarise, the relative charges of protons, neutrons and electrons are as follows:

The relative charges of protons, neutrons and electrons

Flashcards

Flashcards help you memorise information quickly. Copy each question onto its own flashcard and then write the answer on the other side. Testing yourself on these regularly will enable you to learn much more quickly than just reading and making notes.