An Overview of Isotopes : Definition and History

Isotopes are elements with the same number of protons and electrons but a different number of neutrons. Stable isotopes, primordial isotopes, and radioactive isotopes are the three categories. We’ll learn more about isotopes in this article, including examples, types, and uses, as well as the difference between isobars and isotopes.

Isotopes

Chemical species with the same atomic number but different mass numbers are referred to as isotopes. The existence of a distinct number of neutrons in the elements causes the difference in mass number. Isotopes are chemical entities that have the same number of protons and electrons in their nucleus but a different number of neutrons. The isotopes of hydrogen, for example, are hydrogen-1, hydrogen-2, and hydrogen-3. Hydrogen-1 consists of one electron, one proton, and no neutrons; Hydrogen-2 consists of one electron, one proton, and one neutron; and Hydrogen 3 consists of one electron, one proton, and two neutrons. As a result, all three hydrogen isotopes have the same amount of electrons and protons, namely 1, but different numbers of neutrons, thus 0, 1, and 2.

Calculating The Neutrons in An Element

Any element’s nucleus is made up of neutrons and protons. Since neutrons and protons both have a mass of one unit, the total number of neutrons and protons makes up the element’s mass number. As a result, if we know the mass number and the atomic number (because the atomic number equals the number of protons in the nucleus), the difference between the mass number and the atomic number can be used to calculate the number of neutrons present. Tritium, for example, has a mass number of 3 and an atomic number of 1, resulting in: The number of neutrons equals the mass number minus the atomic number. I.e.   No.of Neutrons=Mass No-Atomic No. In tritium, the number of neutrons is 3 – 1 = 2. As a result, tritium has two more neutrons than protium.

Representation of Isotopes

There are two ways to depict isotopes:

• The element’s name is put first, followed by the hyphen and the mass number of the isotope in question. Protium, for example, is represented by Hydrogen-1, Deuterium by Hydrogen-2, and tritium by Hydrogen-3

We use the conventional ZAE notation in this form of representation. The element E is represented by the letter A, the mass number is represented by the letter Z, and the atomic number is represented by the letter Z. The superscript A is written in superscript, and the subscript Z is written in subscript, resulting in ZAE. For example, hydrogen protium has the isotope ₁¹H, Deuterium has the isotope ₁²H, and tritium has the isotope ₁³H.