symmetry of molecules
51Virus — This article is about the biological agent. For other uses, see Virus (disambiguation). For a generally accessible and less technical introduction to the topic, see Introduction to viruses. Viruses …
52Glass transition temperature — The glass transition temperature, T g, is the temperature at which an amorphous solid, such as glass or a polymer, becomes brittle on cooling, or soft on heating. More specifically, it defines a pseudo second order phase transition in which a… …
53Orbital hybridisation — Four sp3 orbitals. Three sp2 orbitals. In …
54Cyclohexane conformation — A cyclohexane molecule in chair conformation. Hydrogen atoms in axial positions are shown in red, while those in equatorial positions are in blue. A cyclohexane conformation is any of several three dimensional shapes that a cyclohexane molecule… …
55Molecular vibration — A molecular vibration occurs when atoms in a molecule are in periodic motion while the molecule as a whole has constant translational and rotational motion. The frequency of the periodic motion is known as a vibration frequency, and the typical… …
56angiosperm — /an jee euh sperrm /, n. Bot. a plant having its seeds enclosed in an ovary; a flowering plant. Cf. gymnosperm. [ANGIO + SPERM] * * * ▪ plant Introduction any member of the more than 300,000 species of flowering plants (division Anthophyta) …
57Coordination complex — Cisplatin, PtCl2(NH3)2 A platinum atom with four ligands In chemistry, a coordination complex or metal complex, is an atom or ion (usually metallic), bonded to a surrounding array of molecules or anions, that are in turn known as ligands or… …
58Arrow of time — This article is an overview of the subject. For a more technical discussion and for information related to current research, see Entropy (arrow of time). In the natural sciences, arrow of time, or time’s arrow, is a term coined in 1927 by British …
59Adamantane — Adamantane …
60Rigid rotor — The rigid rotor is a mechanical model that is used to explain rotating systems. An arbitrary rigid rotor is a 3 dimensional rigid object, such as a top. To orient such an object in space three angles are required. A special rigid rotor is the… …