Columbia Encyclopedia

Search results

274 results found

Geiger counter

(Encyclopedia)Geiger counter or Geiger-Müller (G-M) counter gīˈgər-mŭlˈər, –myo͞oˈlər [key], instrument for the detection and quantitative determination of ionizing radiation such as the alpha and beta ...

germanium

(Encyclopedia)germanium jərmāˈnēəm [key] [from Germany], semimetallic chemical element; symbol Ge; at. no. 32; at. wt. 72.63; m.p. 937.4℃; b.p. 2,830℃; sp. gr. 5.323 at 25℃; valence +2 or +4. Pure german...

frost

(Encyclopedia)frost or hoarfrost, ice formed by the condensation of atmospheric water vapor on a surface when the temperature of the surface is below 32℉ (0℃). In the formation of frost, a gas (water vapor) is ...

Fukushima

(Encyclopedia)Fukushima fo͝oko͞oˈshĭmä [key], city, capital of Fukushima prefecture, N Honshu, Japan, on the Kiso ...

antenna

(Encyclopedia)antenna ăntĕnˈə [key], in electronics, system of wires or other conductors used to transmit or receive radio or other electromagnetic waves (see radio); sometimes called an aerial. The idea of usi...

sun, in astronomy

(Encyclopedia)CE5 Structure of the sun sun, intensely hot, self-luminous body of gases at the center of the solar system. Its gravitational attraction maintains the planets, comets, and other bodies of the sola...

leukemia

(Encyclopedia)leukemia lo͞okēˈmēə [key], cancerous disorder of the blood-forming tissues (bone marrow, lymphatics, liver, spleen) characterized by excessive production of immature or mature leukocytes (white b...

aurora borealis

(Encyclopedia)aurora borealis ôstrāˈlĭs [key], luminous display of various forms and colors seen in the night sky. The aurora borealis of the Northern Hemisphere is often called the northern lights, and the aur...

lymphoma, non-Hodgkin's

(Encyclopedia)lymphoma, non-Hodgkin's, any cancer of the lymphoid tissue (see lymphatic system) in which the Reed-Sternberg cells characteristic of Hodgkin's disease (the other category of lymphoma) are not present...

technetium

(Encyclopedia)technetium tĕknēˈshēəm [key] [Gr. technetos=artificial], artificially produced radioactive chemical element; symbol Tc; at. no. 43; mass no. of most stable isotope 98; m.p. 2,200℃; b.p. 4,877�...