The number of protons, neutrons and electrons in particles A to E are given below:

Give reasons, find a pair of isotopes from the above particles.

The atomic species A and B have different number of protons but the same number of nucleons. On the other hand, the atomic species X and Y have the same number of protons but different number of nucleons. Which pair is an example of isobars? Why?

Composition of the nuclei of two atomic species A and B is given as under:

Give the mass numbers of A and B. What is the relation between the two species and which element or elements they represent?

Which of the following pair is are isobars?

(i)

(ii)

Give reasons for your choice.

The composition of two atomic particles is given below:

(i) What is the mass number of X?

(ii) What is the mass number of Y?

(iii) What is the relation between X and Y?

(iv) Which element/elements do they represent?