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chemical warfare

(Encyclopedia)chemical warfare, employment in war of incendiaries, poison gases, and other chemical substances. Ancient armies attacking or defending fortified cities threw burning oil and fireballs. A primitive ty...

analysis, chemical

(Encyclopedia)analysis, chemical: see chemical analysis. ...

equation, chemical

(Encyclopedia)equation, chemical: see chemical equation. ...

equilibrium, chemical

(Encyclopedia)equilibrium, chemical: see chemical equilibrium. ...

bond, chemical

(Encyclopedia)bond, chemical: see chemical bond. ...

reaction, chemical

(Encyclopedia)reaction, chemical: see chemical reaction. ...

radium

(Encyclopedia)radium rāˈdēəm [key] [Lat. radius=ray], radioactive metallic chemical element; symbol Ra; at. no. 88; mass number of most stable isotope 226; m.p. 700℃; b.p. 1,140℃; sp. gr. about 6.0; valence...

allotropy

(Encyclopedia)allotropy əlŏˈtrəpē [key] [Gr.,=other form]. A chemical element is said to exhibit allotropy when it occurs in two or more forms in the same physical state; the forms are called allotropes. Allot...

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�...

promethium

(Encyclopedia)promethium prōmēˈthēəm [key], artificially produced radioactive chemical element; symbol Pm; at. no. 61; mass no. of most stable isotope 145; m.p. 1,042℃; b.p. 3,000℃ (estimated); sp. gr. unk...