How many meta states does the first isotope to be synthesized in Am in 1944 have?
Americium-241 Americium-241 (Am) is an isotope of americium. Like all isotopes of americium, it is radioactive. Am is the most common isotope of americium. It is the most prevalent isotope of americium in nuclear waste. Americium-241 has a half-life of 432.2 years. It is commonly found in ionization type smoke detectors. It is a potential fuel for long-lifetime radioisotope thermoelectric generators (RTGs). Its common parent nuclides are β from Pu, EC from Cm and α from Bk. Am is fissile and the critical mass of a bare sphere is 57.6-75.6 kilograms and a sphere diameter of 19–21 centimeters. Americium-241 has a specific activity of 3.43 Ci/g (curies per gram or 117.29 gigabequerels (GBq) per gram). It is commonly found in the form of americium-241 dioxide (AmO). This isotope also has one meta state; Am, with an exitation energy of 2.2 MeV, and a half-life of 1.23 μs. Its presence in plutonium is determined by the original concentration of plutonium-241 and the sample age. Because of the low penetration of alpha radiation, americium-241 only poses a health risk when ingested or inhaled. Older samples of plutonium containing plutonium-241 contain a buildup of Am. A chemical removal of americium-241 from reworked plutonium (e.g. during reworking of plutonium pits) may be required in some cases.
Strontium Strontium is the chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly reactive chemically. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally in the minerals celestine, strontianite, and putnisite, and is mined mostly from the first two of these. While natural strontium is stable, the synthetic Sr isotope is radioactive and is one of the most dangerous components of nuclear fallout, as strontium is absorbed by the body in a similar manner to calcium. Natural stable strontium, on the other hand, is not hazardous to health.