St. Peter's Square, Vatican City, Vatican, seen through the Balustrade atop the Basilica. Photo by Elisabetta Villa/Getty Images News/Getty Images. Definition: A balustrade is a row of repeating balusters-small posts that support the upper rail of a railing.Staircases and porches often have balustrades. balustrade is a row of repeating balusters-small posts that support the upper rail of a railing.
dissociation, in chemistry, separation of a substance into atoms or ions. Thermal dissociation occurs at high temperatures. For example, hydrogen molecules (H. The Columbia Electronic Encyclopedia, 6th ed. Copyright Â© 2012, Columbia University Press. All rights reserved.
Inversion, in chemistry, the spatial rearrangement of atoms or groups of atoms in a dissymmetric molecule, giving rise to a product with a molecular configuration that is a mirror image of that of the original molecule. The reaction is usually one in which an atom or a group of atoms in the molecule is replaced by another atom or group. The phenomenon of inversion is sometimes known as Walden inversion, after the German chemist Paul Walden, who discovered it in 1895.