Columbia Encyclopedia
Search results
91 results found
mass spectrograph
(Encyclopedia)mass spectrograph, device used to separate electrically charged particles according to their masses; a form of the instrument known as a mass spectrometer is often used to measure the masses of isotop...seaborgium
(Encyclopedia)seaborgium sēbôrˈgēəm [key], artificially produced radioactive chemical element; symbol Sg; at. no. 106; mass number of most stable isotope 271; m.p., b.p., sp. gr., and valence unknown. Situated...lawrencium
(Encyclopedia)lawrencium, artificially produced radioactive chemical element; symbol Lr; at. no. 103; mass number of most stable isotope 262; m.p. about 1,627℃; b.p. and sp. gr. unknown; valence +3. Lawrencium is...astatine
(Encyclopedia)astatine ăsˈtətēn, –tĭn [key] [Gr.,=unstable], semimetallic radioactive chemical element; symbol At; at. no. 85; at. wt. of most stable isotope 210; m.p. 302℃ (estimated); b.p. 337℃ (estima...einsteinium
(Encyclopedia)einsteinium īnˈstīˌnēəm, īnstīˈ– [key] [for Albert Einstein], artificially produced radioactive chemical element; symbol Es; at. no. 99; mass no. of most stable isotope 252; m.p. about 860...nobelium
(Encyclopedia)nobelium nōbēˈlēəm [key], artificially produced radioactive chemical element; symbol No; at. no. 102; mass no. of most stable isotope 259; m.p. 827℃; b.p. and density unknown; valence +2, +3. I...deuterium
(Encyclopedia)deuterium do͞otērˈēəm [key], isotope of hydrogen with mass no. 2. The deuterium nucleus, called a deuteron, contains one proton and one neutron. Deuterium is also called heavy hydrogen, and water...Richards, Theodore William
(Encyclopedia)Richards, Theodore William, 1868–1928, American chemist, b. Germantown, Pa., Ph.D. Harvard, 1888. Richards was a professor at Harvard from 1891 until his death in 1928. In 1914 he received the Nobel...Boltwood, Bertram Borden
(Encyclopedia)Boltwood, Bertram Borden, 1870–1927, American chemist and physicist, b. Amherst, Mass., grad. Sheffield Scientific School, Yale, 1892. After graduate study at Leipzig and Yale (Ph.D., 1897), he taug...neptunium
(Encyclopedia)neptunium nĕpto͞oˈnēəm [key], radioactive chemical element; symbol Np; at. no. 93; mass number of most stable isotope 237; m.p. about 640℃; b.p. 3,902℃ (estimated); sp. gr. 20.25 at 20℃; va...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 +-
