CBSE Notes, Lectures

CBSE - Chemistry - Structure of the Atom

Structure of the Atom

NCERT Exercise

Composition of the nuclei of two atomic species X and Y are given as under

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

Mass number of X = Number of protons + Number of neutrons

= 6 + 6
= 12 

Mass number of Y = Number of protons + Number of neutrons 
= 6 + 8
= 14

These two atomic species X and Y have the same atomic number, but different mass numbers. Hence, they are isotopes.

.