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 will be the charge on an atom if it gains an electron?

Answer 1

If an atom gains an electron, it will have (a + 1) electrons and a protons

∴ Charge in one electron = –1

∴ Charge in (a + 1) electrons = –1 × (a + 1) = –(a + 1)

∴ Charge in one proton = (+1)

∴ Charge in a protons = (+1) × a = (+ a)

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

= a – (a + 1)

= (–1)