Burning beryllium metal in dry air produces beryllium oxide, BeO.
This is a salt with
ions in a crystal lattice, although the attractions between
have an appreciable covalent character. Since each Be atom can give
up two electrons, and each oxygen atom needs two electrons, the
atoms combine in a 1:1 ratio.
There is an important difference between BeO and
Because beryllium is more electronegative than lithium, the Be-O
bond is not entirely ionic, but has a considerable electron-sharing
character. The electrons that surround an
ion to complete its neon shell actually are shared to a degree with
the beryllium atoms.
BeO is not a completely covalent solid like diamond, but it does
have a partial covalent character that makes it more difficult to
pull apart than .