Chapter 39, Problem 37A

Why are the atomic masses of many elements in the periodic table not whole numbers?

To determine

The reason for atomic masses of all the elements in the periodic table are not whole number.

Explanation of Solution

Introduction:

The mass of all the electrons, protons and neutrons in the atom is called the atomic mass. The mass of the electrons is very less compared to mass of proton and neutron, so the atomic mass of the atom is same as the mass of all protons and neutron in the atom.

There are many isotopes of an element in the nature. The atomic mass of all these isotopes is not possible to show in the periodic table. The average of atomic mass of all isotopes of an element is used to show in the periodic table.

The average of numbers may or may not be whole number. So, the atomic masses of many elements in the periodic table are not whole number.

Conclusion:

Thus, the atomic masses of many elements in the periodic table are not whole number because the average of atomic mass of all the isotopes is shown in the periodic table.