osigma bond: A covalent bond whose electron density is concentrated in the region
directly between the nuclei.
ocovalent bond: A type of chemical bond where two atoms are connected to each
other by the sharing of two or more electrons.
oatomic orbital: A region in space around the atom’s nucleus where there is a
probability of finding an electron.
ovalence electrons: Electrons in the outermost principal energy (valence) level of an
atom that can participate in the formation of chemical bonds with other atoms.
ooctet rule: Atoms lose, gain, or share electrons in order to have a full valence level
of eight electrons. Hydrogen and helium are exceptions because they can hold a
maximum of two valence electrons.
oelectronegativity: The tendency of an atom or molecule to attract electrons and
form bonds.