Examples of isotopes in chemistry are considered on hydrogen. By this term we mean varieties of one chemical element that have the same atomic (ordinal) number, but different mass numbers. In the periodic system of Dmitry Ivanovich Mendeleev, there are many chemical elements, and quite a lot of those that have isotopes that differ in mass number.
Important information
An example of hydrogen isotopes indicates that with different numbers of neutrons, protium, deuterium, tritium have completely different chemical properties.
Most often, an isotope is denoted by the symbol of the element to which it refers, adding an upper left index that defines the mass number. It is also allowed to spell its name with the addition of a hyphen of a mass number. For example, you can see the following options: radon-222, carbon-12.
Considering examples of isotopes in chemistry, we note that some have their own names: tritium, deuterium, and protium.
Terminology features
The term was first proposed in the plural, as it was used to compare two varieties of atoms. The practice has included its use in the singular. Currently, examples of the use of isotopes are uniform in use from the point of view of international scientific organizations.
Discovery story
Analyzing examples of isotopes, it is necessary to dwell on some historical facts. The first evidence that the properties of substances that have the same chemical behavior differ in physical properties was established in the framework of the study of radioactive transformations of atoms of heavy elements.
At the beginning of the nineteenth century it was found that the product of the radioactive decay of the uranium atom is ion, and thorium is formed from thorium, which have similar chemical properties, but differ significantly in atomic mass and radioactive decay characteristics.
A little later it was found that these products have the same x-ray and optical spectra. Substances similar in chemical properties, differing in the mass of atoms and some physical parameters, became known as isotopes (proposed by Soddy in 1910).
An example of isotopes can be seen on the hydrogen atom. Having a similar atomic mass, they differ in the number of neutrons.
By 2016, 3211 isotopes of various chemical elements were discovered, with about 13% of their total number being stable or near-stable, and 40 percent are proton-redundant, that is, they deviate towards neutrons (protons).
It is interesting that the United States, Germany, Great Britain, Russia, France are leaders in discoveries in this area. An example of hydrogen isotopes is analyzed as part of a school chemistry course. The guys analyze the basic concepts: mass number, neutrons, charge number, characterizing protium, deuterium, tritium. Thanks to the discovery of the radioactive theory, it was possible to explain the main differences in the structure and properties of isotopes, to understand the possibilities of their application in various fields of chemistry.