The bonds in BaO are best described as
(1) covalent, because valence electrons are shared
(2) covalent, because valence electrons are transferred
(3) ionic, because valence electrons are shared
(4) ionic, because valence electrons are transferred
The answer is (4) ionic, because valence electrons are transferred. Ba is a metal and O is a nonmetal, so the bond between them is ionic. Ionic bonds occur when electrons are transferred from the metal to the nonmetal, and the cation-anion pair is held together by electrostatic attraction.
