An element of a chemical character identical with that of another element, occupying the same place in the periodic table but differing from it in other characteristics, as in radioactivity or in the mass of its atoms.
A form of a chemical element which has the same chemical properties as other forms but a different atomic mass.
Forms of elements with the same chemical properties, differing in atomic mass because of differing numbers of neutrons in the nucleus. Radioactive isotopes are unstable, and decay to stable elements, emitting radiation in the process. Stable isotopes can be detected only by their different atomic mass. Since they emit no radiation, they are safe for use in labelled compounds given to human beings.
Refers to one of the several “varieties” of atoms that exist, of the same element, that differ from each other in the number of neutrons in the atom’s nucleus. For example, the element chlorine exists primarily in two forms (isotopes) in nature—with 18 neutrons (76% of the time) and with 20 neutrons (24% of the time). The chemical properties of isotopes of a given element are virtually identical.
One of two or more forms of an element having the same atomic number and the same or nearly the same properties but differing in atomic mass (because of difference in number of neutrons in the nucleus); for example, deuterium is an isotope of hydrogen.
One of a variety of forms in which a chemical element can appear. Isotopes of an element are identical in number of protons and electrons in each atom, but differ in mass number (total number of protons and neutrons in each atom’s nucleus), and therefore have different properties.
Different forms of the same chemical element that differ by the number of neutrons in their nucleus. Many naturally occurring elements have several isotopic forms in nature.
Any one of the different forms of an element, possessing the same number of protons (positively charged particles) in the nucleus, and thus the same atomic number, but different numbers of neutrons. Isotopes therefore have different atomic weights. Radioactive isotopes decay into other isotopes or elements, emitting alpha, beta, or gamma radiation. Some radioactive isotopes may be produced artificially by bombarding elements with neutrons. These are known as nuclides and are used extensively in radiotherapy for the treatment of cancer.
This is a form of a chemical element with the same chemical properties as other forms, but which has a different atomic mass. It contains an identical number of positively charged particles called protons in the nucleus, giving it the same atomic number and thus identity as an element, but the numbers of neutrons differ. A radioactive isotope, or radionuclide, is one that has an unstable nucleus and undergoes decay with emission of alpha, beta or gamma radiation.
One of a series of chemical elements that have nearly identical chemical properties but different atomic weights and electric charges. Many isotopes are radioactive.
There exist various manifestations of a specific chemical entity, each exhibiting a distinct and individual atomic weight.
Atoms possessing an identical count of nuclear protons, corresponding to the atomic number, albeit exhibiting varied quantities of nuclear neutrons.
An assortment of two or more variants of atomic units belonging to a specific chemical element, sharing an equivalent atomic number and displaying nearly indistinguishable chemical characteristics, yet diverging in terms of atomic mass and physical attributes.
Any individual variation of atoms within a chemical element. Distinct isotopes of an element share an identical count of protons (positively charged particles) while having differing quantities of neutrons (particles with no charge) in their nucleus, resulting in a distinct atomic weight for each.
Unstable radioactive isotopes undergo decay to transform into more stable configurations, emitting electromagnetic radiation during the process. This emission of radiation renders these isotopes suitable for certain medical applications, including cancer radiotherapy and diagnostic imaging methods like radionuclide scanning.
An element that has the same atomic number as another but a distinct atomic weight. Many prevalent elements are made up of multiple isotopes, with the element’s observed atomic weight reflecting the average weight of all its isotopes.