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sublimation, in chemistry

(Encyclopedia)sublimation sŭblĭmāˈshən [key], change of a solid substance directly to a vapor without first passing through the liquid state. The term is also used to describe the reverse process of the gas ch...

capillary

(Encyclopedia)capillary kăpˈəlĕrˌē [key], microscopic blood vessel, smallest unit of the circulatory system. Capillaries form a network of tiny tubes throughout the body, connecting arterioles (smallest arter...

flame

(Encyclopedia)flame, phenomenon associated with the chemical reaction of a gas that has been heated above its kindling temperature with some other gas, usually atmospheric oxygen (see combustion). The heat and ligh...

aluminum

(Encyclopedia)aluminum ălˌyo͞omĭnˈēəm [key], metallic chemical element; symbol Al; at. no. 13; at. wt. 26.98154; m.p. 660.37℃; b.p. 2,467℃; sp. gr. 2.6989 at 20℃; valence +3. Aluminum is a silver-white...

molecule

(Encyclopedia)molecule mŏlˈəkyo͞ol [key] [New Lat.,=little mass], smallest particle of a compound that has all the chemical properties of that compound. A single atom is usually not referred to as a molecule, a...

mercaptan

(Encyclopedia)mercaptan thīˈōl [key], any of a class of organic compounds containing the group –SH bonded to a carbon atom. The volatile low-molecular-weight mercaptans have disagreeable odors. Mercaptans are ...

Liebig, Justus, Baron von

(Encyclopedia)Liebig, Justus, Baron von yo͝osˈto͝os bärônˈ fən lēˈbĭkh [key], 1803–73, German chemist. As professor at Giessen (1824–52), he was among the first to establish a chemical teaching labora...

mass number

(Encyclopedia)mass number, often represented by the symbol A, the total number of nucleons (neutrons and protons) in the nucleus of an atom. All atoms of a chemical element have the same atomic number (number of pr...

graphene

(Encyclopedia)graphene, virtually transparent, highly conductive carbon material in which the atoms are organized into a honeycomblike arrangement and form a thin sheet that is one atom thick. Andre Geim and Konsta...

formic acid

(Encyclopedia)formic acid or methanoic acid mĕthˌənōˈĭk [key], HCO2H, a colorless, corrosive liquid with a sharp odor; it boils at 100.7℃ and solidifies at 8.4℃. It has the lowest molecular weight and is ...