Useful english dictionary. 2012.
Tetrahedron — For the academic journal, see Tetrahedron (journal). Regular Tetrahedron (Click here for rotating model) Type Platonic solid Elements F = 4, E = 6 V = 4 (χ = 2) Faces by s … Wikipedia
Charles Henry Hitchcock — (1836–1919) was an American geologist. Life Hitchcock was born August 23, 1836 in Amherst, Massachusetts.[1] His father was Edward Hi … Wikipedia
chemical bonding — ▪ chemistry Introduction any of the interactions that account for the association of atoms into molecules, ions, crystals, and other stable species that make up the familiar substances of the everyday world. When atoms approach one another … Universalium
physical science — physical scientist. 1. any of the natural sciences dealing with inanimate matter or with energy, as physics, chemistry, and astronomy. 2. these sciences collectively. [1835 45] * * * Introduction the systematic study of the inorganic world … Universalium
fern — fernless, adj. fernlike, adj. /ferrn/, n. any seedless, nonflowering vascular plant of the class Filicinae, of tropical to temperate regions, characterized by true roots produced from a rhizome, triangular fronds that uncoil upward and have a… … Universalium
Fern — /ferrn/, n. a female given name. * * * Any of about 10,000–12,000 species (division Filicophyta) of nonflowering vascular plants that have true roots, stems, and complex leaves and reproduce by spores. Though ferns were once classified with the… … Universalium
Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… … Universalium
Cyclol — Figure 1: In the classic cyclol reaction, two peptide groups are linked by a N C’ bond, converting the carbonyl oxygen into a hydroxyl group. Although this reaction occurs in a few cyclic peptides, it is disfavored by free energy, mainly because… … Wikipedia
Evolution — Evolution (History and Scientific Foundation) † Catholic Encyclopedia ► Evolution (History and Scientific Foundation) The world of organisms comprises a great system of individual forms generally classified according to structural… … Catholic encyclopedia
History of the molecule — In chemistry, the history of the molecule traces the origins of the concept or idea of the existence of strong chemical bonds between two or more atoms. The modern concept of molecules can be traced back towards pre scientific Greek philosophers… … Wikipedia
