Composition of the nuclei of two atomic species X and Y are given as under : X Y Protons = 6 6 Neutrons = 6 8 Give the mass numbers of X and Y. What is the relation between the two species?

Answer :
We know that :
Mass number of an atom  = Number of Protons + number of Neutrons
 Atomic Number of an atom= Number of Protons
:.  Atomic Number of X =  6
:.  Atomic Number of y =  6
:. Mass number of X =  6+6 = 12
:.  Mass number of  y = 6+8 = 14
X and Y have similar  Atomic Number (6) but have different mass numbers, therefor both are isotopes of same element.

This is an answered question from Chapter 4. Structure Of The Atom of CBSE Class 9th Science

Check for Complete Exercise Solution for Chapter 4. Structure Of The Atom | CBSE Class 9th Science