Friday, July 9, 2010
ISOTOPES
What are isotopes?
What are isotopes?
Isotopes are atoms of the same element that have different number of neutrons.
Examples of Isotopes:
Hydrogen.
Hydrogen has no neutrons at all but there is also a hydrogen isotope called deuterium with one neutron and tritium with two neutrons.
Radioactive Isotopes
-Also known as radioisotopes
-Are atoms with a different number of neutrons than a usual atom with an unstable nucleus that decays, emitting alpha, beta and gamma rays until the isotope reaches stability. Once it is stable, the isotope becomes another element entirely. Radioactive decay is spontaneous so it is often hard to know when it will take place or what sort of rays it will emit during decay.
-There are around 3800 radioactive isotopes. 200 radioactive isotopes used on a regular basis. While some are found in nature, most others have to be manufactured to suit specific needs, such as for hospitals , research labs and manufacturers.
-Radioactive isotopes can be manufactured in several ways, the most common by neutron activation in a nuclear reactor which involves capturing a neutron by the nucleus of an atom which results in an excess of neutrons. Some radioactive isotopes are produced in a cyclotron in which protons are introduced to a nucleus resulting in a deficiency of neutrons.
-Radioactive isotopes have very useful properties. Alpha, beta and gamma radiation can permeate solid objects like an x-ray, but are progressively absorbed by them. The amount of penetration depends on a several factors including the energy of the radiation, mass of particle, and density of the solid. These properties can lead to many uses for radioisotopes in the scientific, medical, archaeological and industrial fields. The uses of radioactive isotopes in these fields depend on what element they become after they reach stability.
11:00 PM
