Question 1 Page 52 (Right) - Chapter 4 Class 9 - Structure of Atom

If, number of electrons in an atom is 8 and the number of protons is also 8, then (i) what is the atomic number of the atom? and (ii) what is the charge on the atom?

Answer

Given: Number of electrons in an atom = Number of protons = 8

(i) Atomic Number

We know that,

Number of electrons in an atom = Number of protons = Atomic Number of the atom 

Therefore, Atomic number = 8

(ii) Charge of atom

Charge of a proton = +1

Charge of 8 protons = 8 x (+1) = +8

Charge of an electron = -1

Charge of 8 electrons = 8 x (-1) = -8

Hence total charge on the atom = charge of 8 protons + charge of 8 electrons

                                                      = 8 + (-8)

                                                       = 0

Therefore, charge on the atom is 0.