Columbia Encyclopedia
Search results
500 results found
roentgenium
(Encyclopedia)roentgenium, artificially produced radioactive chemical element; symbol Rg; at. no. 111; mass number of most stable isotope 280; m.p., b.p., sp. gr., and valence unknown. Situated in Group 11 of the p...Cronstedt, Axel Fredrik, Baron
(Encyclopedia)Cronstedt, Axel Fredrik, Baron äkˈsəl frāˈdrĭk, kro͞onˈstĕt [key], 1722–65, Swedish mineralogist and chemist. In 1751 he discovered in niccolite an impure form of nickel, reported it as a n...iridium
(Encyclopedia)iridium ĭrĭdˈēəm [key], metallic chemical element; symbol Ir; at. no. 77; at. wt. 192.217; m.p. about 2,410℃; b.p. about 4,130℃; sp. gr. 22.55 at 20℃; valence +3 or +4. Iridium is a very ha...americium
(Encyclopedia)americium ămərĭˈshēəm [key], artificially produced radioactive chemical element; symbol Am; at. no. 95; mass no. of most stable isotope 243; m.p. about 1,175℃; b.p. about 2,600℃; sp. gr. 13....peroxide
(Encyclopedia)peroxide pərŏkˈsīd [key], chemical compound containing two oxygen atoms, each of which is bonded to the other and to a radical or some element other than oxygen; e.g., in hydrogen peroxide, H2O2, ...Lead B
(Encyclopedia)Lead Belly, nickname of Huddie William Ledbetter, 1885–1949, American singer, b. Mooringsport, La. While wandering through Louisiana and Texas, he...Shymkent
(Encyclopedia)Shymkent chĭmkyĕntˈ [key], city (1993 est. pop. 404,000), S Kazakhstan, on the Turkistan-Siberia RR. It has large zinc and lead smelters and machine, chemical, and food-processing industries. Found...nihonium
(Encyclopedia)nihonium nĭhōˈnēəm [key], artificially produced radioactive chemical element; symbol Nh; at. no. 113; mass number of most stable isotope 284; m.p., b.p., sp. gr., and valence unknown. Situated in...periodic table
(Encyclopedia) CE5 periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arrange...symbol
(Encyclopedia)symbol, sign representing something that has an independent existence. The most important use of symbols is in language. To say so, however, does not solve the perennial philosophical questions as to ...Browse by Subject
- Earth and the Environment +-
- History +-
- Literature and the Arts +-
- Medicine +-
- People +-
- Philosophy and Religion +-
-
Places
+-
- Africa
- Asia
- Australia and Oceania
- Britain, Ireland, France, and the Low Countries
- Commonwealth of Independent States and the Baltic Nations
- Germany, Scandinavia, and Central Europe
- Latin America and the Caribbean
- Oceans, Continents, and Polar Regions
- Spain, Portugal, Italy, Greece, and the Balkans
- United States, Canada, and Greenland
- Plants and Animals +-
- Science and Technology +-
- Social Sciences and the Law +-
- Sports and Everyday Life +-
