Question

The composition of two atomic particles is given below :

	X	Y
Protons :	8	8
Neutrons :	8	9
Electrons :	8	8

(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 ?

Answer 1

(i) Mass number of X = 8+8 = 16
(ii) Mass number of Y = 8+9 = 17
(iii) X and Y are isotopes, as they have the same number of protons but different number of neutrons.
(iv) X and Y represent the isotopes of oxygen.