Question

Question 13 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?

Class 9 - Science - Structure of the Atom Page 55

Answer 1

Heya !

Here is your answer =======================================================================

>> We know that :

Mass number = No. of protons + No. of neutrons

So, Mass number of X = 6 + 6
= 12

Mass number of Y = 6 + 8
= 14

Thus, the mass number of X is 12 and that of Y is 14.

Now , X contains 6 protons, therefore, the atomic number of X is 6. Y contains 6 protons, therefore, the atomic number of Y is also 6. Since X and Y have the same atomic number (of 6) but different mass numbers (of 12 and 14) , they are a pair of isotopes. Atomic number 6 is of carbon element. So, both X and Y represent carbon element.

Answer 2

Heya,

Given,

Composition of nuclei of  X = 6 protons and 6 neutrons

Mass number = 6 + 6 = 12

Composition of nuclei of Y = 6 protons and 8 neutrons

Mass number = 6 + 8 = 14

These species are known as isobars as they have same atomic number but different atomic masses.

Hope it helps u....