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.
The Covalent Bond. Atoms can combine to achieve an octet of valence electrons by sharing electrons. Two fluorine atoms, for example, can form a stable F2 molecule in which each atom has an octet of valence electrons by sharing a pair of electrons. A pair of oxygen atoms can form an O2 molecule in which each atom has a total of eight valence electrons by sharing two pairs of electrons. The term covalent bond is used to describe the bonds in compounds that result from the sharing of one or more pairs of electrons.