ion pair
121chemical compound — Introduction any substance composed of identical molecules consisting of atoms (atom) of two or more chemical elements (chemical element). All the matter in the universe is composed of the atoms of more than 100 different chemical elements …
122nervous system — Anat., Zool. 1. the system of nerves and nerve centers in an animal or human, including the brain, spinal cord, nerves, and ganglia. 2. a particular part of this system. Cf. autonomic nervous system, central nervous system, peripheral nervous… …
123coordination compound — Chem. complex (def. 10). Also called coordination complex. * * * ▪ chemistry Introduction any of a class of substances with chemical structures in which a central metal atom is surrounded by nonmetal atoms or groups of atoms, called ligands… …
124Nucleic acid tertiary structure — Example of a large catalytic RNA. The self splicing group II intron from Oceanobacillus iheyensis.[1] The tertiary structure of a nucleic acid is its precise three dimensional structure, as defined by the atomic coordinates.[2] …
125Mathematics 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… …
126Acid — This article is about acids in chemistry. For the drug, see Lysergic acid diethylamide. For other uses, see Acid (disambiguation). Acidity redirects here. For the novelette, see Acidity (Novelette). Acids and Bases …
127Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… …
128chemical reaction — Any chemical process in which substances are changed into different ones, with different properties, as distinct from changing position or form (phase). Chemical reactions involve the rupture or rearrangement of the bonds holding atoms together… …
