What are Epididymitis and Orchitis? Pain in the scrotum or testicle (âtesteâ) might be from epididymitis, orchitis or both. Epididymitis is swelling or pain in the back of the testicle in the coiled tube (epididymis) that stores and carries sperm.
Share. By Anne Marie Helmenstine, Ph.D. Definition: Valence bond theory is a chemical bonding theory that explains the bonding between two atoms is caused by the overlap of half-filled atomic orbitals. The two atoms share each other's unpaired electron to form a filled orbital to form a hybrid orbital and bond together.
In chemistry, a valence electron is an electron that is associated with an atom, and that can participate in the formation of a chemical bond; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.ecause the number of valence electrons which actually participate in chemical reactions is difficult to predict, the concept of the valence electron is less useful for a transition metal than for a main group element; the d electron count is an alternative tool for understanding the chemistry of a transition metal.