Question

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

	A	B
Protons:	18	20
Neutrons:	22	20

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

Answer 1

The mass number of A = Number of proton + Number of neutrons
The mass number of A = 18 + 22
The mass number of A = 40
Number of electrons of A = 18

The mass number of B = Number of proton + Number of neutrons
The mass number of B = 20 + 20
The mass number of B = 40
Number of electrons of B = 20

There is no relation between the two species.
As specie A, represents argon.
As specie B, represents calcium.
Argon(A) is a noble gas element, argon does not form any molecule with calcium(B).