many of these compounds are not formed in any
121Complex (chemistry) — The term complex in chemistry is usually used to describe molecules or ensembles formed by the combination of ligands and metal ions. Originally, a complex implied a reversible association of molecules, atoms, or ions through weak chemical bonds …
122Transition metal — The term transition metal (sometimes also called a transition element) has two possible meanings: The IUPAC definition[1] states that a transition metal is an element whose atom has an incomplete d sub shell, or which can give rise to cations… …
123Pregnancy — For pregnancy in non human animals, see Pregnancy (mammals). Pregnancy Classification and external resources A pregnant woman at the end of the second trimester. ICD 10 …
124Geology of Mars — Mars   Mars as seen by the Hubble Space Telescope Designations …
125insect — insectival /in sek tuy veuhl/, adj. /in sekt/, n. 1. any animal of the class Insecta, comprising small, air breathing arthropods having the body divided into three parts (head, thorax, and abdomen), and having three pairs of legs and usually two… …
126carbon group element — ▪ chemical elements Introduction any of the five chemical elements that make up Group 14 (IVa) of the periodic table namely, carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead ( …
127Fullerene — Buckminsterfullerene C60 (left) and carbon nanotubes (right) are two examples of structures in the fullerene family …
128Classical compound — Classical compounds (also known as neoclassical compounds, and combining forms) are compound words composed from Latin or Ancient Greek root words. A large portion of the technical and scientific lexicon of English and other Western European… …
