The properties of any matter depend on the atomic configuration. The number of protons contributes to the atomic number and the number of protons and neutrons contributes to the atomic mass. Each element has a unique atomic number. Isotopes are two atoms with the same atomic number but different atomic masses. On the other hand, isobars are two atoms with the same atomic mass but different atomic numbers. In this article, we discuss 10 differences between isotopes and isobars.
| Parameters | Isotopes | Isobars |
| DEFINITION | Isotopes are one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table. | Isobars are atoms with the same atomic mass number but a different number of protons and neutrons. |
| PHYSICAL PROPERTIES | The physical properties of isotopes are different. | Isobars mostly have similar physical properties. |
| PROPERTIES | The chemical properties of isotopes do not differ much as the number of protons is the same. But, in the case of hydrogen atoms, the difference in properties is huge due to a major impact on the size of the nucleus. | Isobars have totally different chemical properties. |
| APPLICATION | • Cobalt-60 is widely used as a radiation source in radiotherapy for cancer treatment. •Other uses are used as traces for diagnostic purposes as well as in research on metabolic processes. •In industry, they are used in measuring the thickness of metals or plastic silver. • They are employed to examine structural defects in metal parts. | •Nuclear reactors can use uranium’s isobars. •Iodine’s isobars are used in goiter treatment. |
| PLACE IN PERIODIC TABLE | Isotopes occur in the same place in the periodic table. | Isobars do not occur at the same place, they can be anywhere across the periodic table. |
| ATOMIC NUMBER | Isotopes have the same atomic number. | Isobars have different atomic numbers. |
| ATOMIC MASS | Isotopes have different atomic masses. | Isobars have the same atomic mass. |
| Protons | Isotopes have the same number of protons. | Isobars have a different number of protons. |
| NEUTRONS | Isotopes have different numbers of neutrons. | Isobars have different numbers of neutrons. |
| EXAMPLES | Carbon-12, Carbon-13, and Carbon-14 are the three isotopes of the element carbon with mass numbers 12, 13, and 14 respectively. | The 40S, 40Cl, 40Ar, 40K, and 40Ca are some of examples of isobars where they contain varying numbers of Protons and Neutrons but have a common mass number of 40. |
Difference between isotopes and isobars with example
Let us take the example of a hydrogen atom to understand an isotope.
A hydrogen atom has one proton and no neutron. But, it has two isotopes deuterium and tritium which have one and 2 neutrons respectively. We can see that the number of protons remains the same but the number of neutrons varies.
But an isobar on the other hand has a varied number of both protons and neutrons with a constant sum of protons and neutrons. Let us take the common isobar example of 40Ar, 40K, and 40Ca, where the number of protons and neutrons vary, but the number of nucleons remains the same.
