actinium series
41astatine — /as teuh teen tin/, n. Chem. a rare element of the halogen family. Symbol: At; at. no.: 85. [1945 50; < Gk ástat(os) not steadfast, unstable (see ASTATIC) + INE2] * * * ▪ chemical element Introduction radioactive chemical element and the… …
42thallium — /thal ee euhm/, n. Chem. a soft, malleable, rare, bluish white metallic element: used in the manufacture of alloys and, in the form of its salts, in rodenticides. Symbol: Tl; at. wt.: 204.37; at. no.: 81; sp. gr.: 11.85 at 20°C. [1860 65; < NL,… …
43nobelium — /noh bel ee euhm, bee lee /, n. Chem., Physics. a transuranic element in the actinium series. Symbol: No; at. no.: 102. [1955 60; < NL; after NOBEL Institute, where first discovered; see IUM] * * * ▪ chemical element (No), synthetic chemical… …
44nobelium — no•bel•i•um [[t]noʊˈbɛl i əm, ˈbi li [/t]] n. phs chem. a transuranic element in the actinium series. Symbol: No; at. no.: 102 • Etymology: 1957; named in honor of Alfred Nobel and the Nobel Institute for Physics in Stockholm …
45uranium 235 — noun a uranium isotope with mass number 235; capable of sustaining chain reactions • Hypernyms: ↑uranium, ↑U, ↑atomic number 92 * * * noun : a light isotope of uranium of mass number 235 that is physically separable from natural uranium or is… …
46Actinide — The atomic bomb dropped on Nagasaki had a plutonium charge.[1] The actinide or actinoid (IUPAC nomenclature) series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium thro …
47Actinoid — The actinoid (according to current IUPAC terminology; previously actinide) series encompasses the 15 chemical elements that lie between actinium and lawrencium included on the periodic table, with atomic numbers 89 103. [… …
48Radon — This article is about the chemical element. For other uses, see Radon (disambiguation). astatine ← radon → francium Xe ↑ Rn ↓ Uuo …
49Francium — radon ← francium → radium Cs ↑ Fr ↓ Uue …
50Alkali metal — Group → 1 ↓ Period 2 3 Li 3 …
