Radioiodine is the common name for iodine-131, a radioisotope of iodine. A radionuclide is an atom with an unstable nucleus. ... General Name, Symbol, Number iodine, I, 53 Series halogens Group, Period, Block 17 (VIIA), 5, p Density, Hardness 4940 kg/m3, no data Appearance violet-dark grey, lustrous Atomic properties Atomic weight 126. ...

Iodine-131 decays with a half life of 8 days with beta and gamma emissions. An iodine atom has an atomic number of 53, showing that it has 53 protons in its nucleus. Therefore iodine-131 with its mass number of 131 has 78 neutrons (131 minus 53). On decaying, iodine-131 transforms into xenon-131. Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Beta particles are high-energy electrons emitted by certain types of radioactive nuclei such as potassium-40. ... This article is about electromagnetic radiation. ... Properties For alternative meanings see atom (disambiguation). ... The atomic number (Z) is a term used in chemistry and physics to represent the number of protons found in the nucleus of an atom. ... For alternative meanings see proton (disambiguation). ... The nucleus (atomic nucleus) is the center of an atom. ... The mass number (A), also called atomic mass number or nucleon number, is the number of protons and neutrons in an atomic nucleus. ... Properties In physics, the neutron is a subatomic particle with no net electric charge and a mass of 940 MeV/c² (1. ... General Name, Symbol, Number xenon, Xe, 54 Chemical series Noble gases Group, Period, Block 18 (VIIIA), 5, p Density, Hardness 5. ...

It is used in nuclear medicine both diagnostically and therapeutically. Examples of its use in therapy include the treatment of thyrotoxicosis and cancer of the thyroid. Diagnostic tests exploit the mechanism of absorption of iodine by the normal cells of the thyroid gland. As an example iodine-131 is one of the radioactive isotopes of iodine that can be used to test how well the thyroid gland is functioning. Nuclear medicine is the branch of medicine that uses unsealed radioactive substances in diagnosis and therapy. ... Hyperthyroidism (thyrotoxicosis or fast thyroid gland) is the clinical syndrome caused by an excess of circulating free thyroxine (T4) and free triiodothyronine (T3), or both. ... Thyroid cancer is cancer of the thyroid gland. ... The thyroid gland and its relations In anatomy, the thyroid (IPA θaɪɹoɪd) is an endocrine gland. ...

Iodine-131 is also used as a radioactive label for radiopharmaceuticals that can be used for imaging and therapy e.g. I131-metaiodobenzylguanidine (I-131-MIBG) for imaging and treating phaeochromocytoma and neuroblastoma. A radiopharmaceutical is a radioactive pharmaceutical. ... Neuroblastoma is the most common extracranial solid cancer in infancy and childhood. ...