Note: In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A): All isotopes of a given element show the same type of chemical behaviour.

Reason (R): The chemical properties of an atom are controlled by the number of electrons in the atom.

Electrons usually take part in chemical reactions and also responsible for certain chemical behaviour of an element because they are determined by the numbers of protons in the nucleus.

When it comes to isotopes they show resemblance in chemical nature and behaviours to other substances.

This is due to an equal number of protons i.e. also equal electrons present in then which controls their chemical properties.

Hence, the given Assertion (A) is correct and Reason (R) can explain it properly (i) Both A and R are true and R is the correct explanation of A. Is the right answer.

Other 3 options (ii) Both A and R are true but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) Both A and R are false are incorrect.