Question

An atom consists of charged particles called electrons and protons. Each proton has a charge of +1 and each electron has a charge of –1. Remember number of electrons is equal to number of protons, while answering these questions:

What is the charge on an atom?

Answer 1

Let a be the number of electrons in an atom.

Number of protons in the atom, will also be equal to a. Since, an atom has equal number of protons and electrons.

∴ Charge on one electron = (–1)

∴ Total charge in a electrons = a × (–1) = –a

∴ Charge on one proton = (+1)

∴ Total charge in a protons = a × (+1) = + a

Hence, total charge on the atom = Charge of electrons + Charge of protons

= –a + a

= 0