Chapter 15, Problem 14RQ

To determine

The occurrence of atoms to be isotope of each other

Answer to Problem 14RQ

The atoms are said to be isotope of each other if they have same atomic number but different mass number i.e., the number of neutrons in their nucleus are different.

Explanation of Solution

The mass number defines the number of neutrons in the nucleus of an atom and is mostly used in deciding the radioactive property of the atom.

Write the expression for the mass number.

$\text{Mass number }=\text{ number of protons }+\text{ number of neutrons}$

For the atoms to be an isotope of each other, the atom must have an equal atomic number but a different mass number. From the above relation, for a different mass number and same atomic number, the number of neutrons should be different in the atoms, and so if the number of neutrons is different in the atoms, then their radioactive nature will also differ.

Conclusion:

Therefore, the atoms are said to be isotope of each other if they have same atomic number but different mass number i.e., the number of neutrons in their nucleus are different.