noun. A white metallic transuranic element of the actinide series, having isotopes with mass numbers from 232 to 247. Am-241 and Am-243 are the isotopes with the longest half-lifes (432.2 years and 7,370 years, respectively), and are alpha-ray and gamma-ray emitters used as radiation sources in research, radiography, and smoke alarms. Atomic number 95; melting point 1176°C; boiling point 2011°C; specific gravity 12; valence 3, 4, 5, 6. cross-reference: Periodic Table.

noun. The chemical element (symbol Am) with an atomic number of 95.

noun. a radioactive transuranic metallic element; discovered by bombarding uranium with helium atoms

"Barot wrote a letter to the leaders of al-Qaeda proposing that he would mine the small amount of radioactive material known as americium that can be found in ordinary smoke detectors and use it to build a radiological device."

America  American  

americium bromide  americium chloride  americium dioxide  americium fluoride  americium iodide  

metal  metallic element  

Arne  botulism  catecholamine  cesium  g-linolenic