What Are the Charges of Protons, Neutrons and Electrons?

A proton has a relative charge of $+1$, a neutron has a relative charge of $0$, and an electron has a relative charge of $-1$. In a neutral atom, the positive and negative charges cancel because there are equal numbers of protons and electrons.

This article covers section $\mathrm{4.1.1.4}$ of AQA GCSE Chemistry $8462$, separate science, at both Foundation and Higher tiers.

What does relative charge mean?

A relative charge compares the electrical charges of particles using simple numbers. A proton’s charge and an electron’s charge are equal in size but opposite in sign. A neutron has no electrical charge, so it does not affect the total.

Protons and neutrons are found in the nucleus, at the centre of an atom. Electrons occupy shells around the nucleus. The number of protons is called the atomic number. It determines which element the atom is: changing the number of electrons does not change the element.

How do the charges cancel?

Each proton contributes $+1$ and each electron contributes $-1$. A neutral sodium atom, for example, has $11$ protons and $11$ electrons. Its overall charge is

$$(11\times +1)+(11\times -1)=0.$$

You do not need to count its neutrons when finding the overall charge, because each neutron contributes $0$. To check any atom’s charge, compare the number of protons with the number of electrons: equal numbers mean the atom is neutral.

What if an electron is lost?

If that sodium atom loses one electron, it still has $11$ protons but now has $10$ electrons. The charges no longer cancel: $11-10=+1$. It is now a positive ion, meaning an atom with an overall electrical charge. Losing an electron makes the charge more positive; it does not remove a proton from the nucleus.

Common exam mistake: A neutron is not negative, despite its name. Its relative charge is $0$; the electron has charge $-1$.