Question

Question 110 (iii)

Science Application An atom consists of charged particles called electrons and protons. Each proton has a charge of +1 and each electron has a charge -1. Remember the number of electrons is equal to the number of protons, while answering this question :
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
$\therefore$ Charge in one electron = -1
Charge in (a + 1) electrons = -1 $\times$ (a + 1) = - (a + 1)
$\therefore$ Charge in one proton = (+1)
Charge in protons = (+1) $\times$ a = (+a)
Hence, total charge on the atom = Charge of electrons + Charge of protos = a - (a + 1) = (-1)