A covalent compound is a compound in which the atoms are held together by covalent bonds. Covalent bonds are formed when two atoms share electrons. In dinitrogen trioxide, the nitrogen atoms share three pairs of electrons, forming three covalent bonds.
An ionic compound is a compound in which the atoms are held together by ionic bonds. Ionic bonds are formed when one atom transfers electrons to another atom. There are no ionic bonds in dinitrogen trioxide.
