What do you mean by isotopes?
Answers
Answer:
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
Answer:
Isotopes can be defined as the variants of chemical elements that possess the same number of protons and electrons, but a different number of neutrons. In other words, isotopes are variants of elements that differ in their nucleon numbers due to a difference in the total number of neutrons in their respective nuclei. For example, carbon-14, carbon-13, and carbon-12 are all isotopes of carbon. Carbon-14 contains a total of 8 neutrons, carbon-13 contains a total of 7 neutrons, and carbon-12 contains a total of 6 neutrons.
Isotopes are primarily represented in two different ways:
By writing the name of the element followed by a hyphen and the mass number of the isotope. For example, uranium-235 and uranium-239 are two different isotopes of the element uranium.
By following the AZE notation (also known as the standard notation). This involves writing the symbol of an element and prefixing the atomic number in subscript and the mass number in superscript. For example, the uranium-235 isotope can be represented as 23592U and the uranium-239 isotope can be represented as 23992U.
Determining the Number of Neutrons in an Isotope
The total number of neutrons in the nucleus of an isotope can be determined by subtracting the atomic number of the element from the mass number of the isotope. For example, the 12C isotope of carbon has a mass number of 12. The atomic number of carbon is 6. Therefore, the total number of neutrons in the carbon-12 isotope is equal to 6.
Stable Isotopes, Primordial Isotopes, and Radioactive Isotopes
Some isotopes have unstable atomic nuclei that undergo radioactive decay. These isotopes are radioactive in nature and are, therefore, known as radioisotopes (or radionuclides). Examples of radioactive isotopes include carbon-14, tritium (hydrogen-3), chlorine-36, uranium-235, and uranium-238.
Some isotopes are known to have extremely long half-lives (in the order of hundreds of millions of years). Such isotopes are commonly referred to as stable nuclides or stable isotopes. Common examples of stable nuclides include carbon-12, carbon-13, oxygen-16, oxygen-17, and oxygen-18.
Primordial nuclides are the nuclides that have existed since the formation of the solar system. Of the 339 naturally occurring isotopes on Earth, a total of 286 isotopes are known to be primordial isotopes.