Carbon 5, years Used to measure the age of organic material up to 50, years old. Chlorine , years Used to measure sources of chloride and the age of water up to 2 million years old. Lead Chromium Manganese Produced in reactors. Cobalt 5. Also used to irradiate fruit fly larvae in order to contain and eradicate outbreaks, as an alternative to the use of toxic pesticides. Zinc Produced in cyclotrons. Technetiumm 6. Produced in 'generators' from the decay of molybdenum, which is in turn produced in reactors.
Caesium Ytterbium Iridium Also used to trace sand to study coastal erosion. Gold 2. Also used to trace factory waste causing ocean pollution, and to study sewage and liquid waste movements. Americium Radioisotope Half-life Use Phosphorus Yttrium 64 hours Used for liver cancer therapy.
Molybdenum Iodine 8. Samarium Lutetium 6. Used to treat a variety of cancers, including neuroendocrine tumours and prostate cancer. Radioisotope Half-life Use Carbon Also used to detect heart problems and diagnose certain types of cancer.
Nitrogen 9. Another example is iodine, an element essential for health; insufficient iodine in one's diet can lead to a goiter. Iodine also is one of the earliest elements whose radioisotopes were used in what is now called nuclear medicine.
The most common, stable form of iodine has an atomic number of 53 protons and an atomic weight of 53 protons plus 74 neutrons. Because its nucleus has the "correct" number of neutrons, it is stable and is not radioactive. A less stable form of iodine also has 53 protons this is what makes it behave chemically as iodine but four extra neutrons, for a total atomic weight of 53 protons and 78 neutrons.
With "too many" neutrons in its nucleus, it is unstable and radioactive, with a half-life of eight days. Because it behaves chemically as iodine, it travels throughout the body and localizes in the thyroid gland just like the stable form of iodine.
But, because it is radioactive, its presence can be detected. Iodine thus became one of the earliest radioactive tracers. How can different isotopes of an element be produced? How can isotopes be produced--especially radioisotopes, which can serve many useful purposes? There are two basic methods: separation and synthesis.
Some isotopes occur in nature. If radioactive, these usually are radioisotopes with very long half-lives. Isotopes can be stable or unstable or radioisotopes. In the latter, their nuclei have a special property: they emit energy in the form of ionizing radiation while searching for a more stable configuration. Isotopes are the atoms in an element that have the same atomic number but a different atomic mass. The atomic number defines the chemical element that the atom belongs to.
Thus, regardless of the number of neutrons they have, all atoms whose nuclei have one proton are hydrogen atoms. All of those with eight protons are oxygen atoms, etcetera. The ionizing radiation that is emitted can include alpha particles alpha particles A form of particulate ionizing radiation made up of two neutrons and two protons.
Alpha particles pose no direct or external radiation threat; however, they can pose a serious health threat if ingested or inhaled. Some beta particles are capable of penetrating the skin and causing damage such as skin burns. Beta-emitters are most hazardous when they are inhaled or swallowed. Gamma rays can pass completely through the human body; as they pass through, they can cause damage to tissue and DNA.
Radioactive decay occurs in unbalanced atoms called radionuclides. Elements in the periodic table can take on several forms. Some of these forms are stable; other forms are unstable. Typically, the most stable form of an element is the most common in nature.
However, all elements have an unstable form.
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