Final answer:
Lithium oxide has a higher melting point than carbon monoxide because it is an ionic compound with a strong ionic lattice, requiring more energy to break apart compared to the weaker covalent bonds in carbon monoxide.
Step-by-step explanation:
The significantly higher melting point of lithium oxide compared to carbon monoxide can be attributed to the type of bonding and structural differences between the two compounds. Carbon monoxide is a covalent molecule with a triple covalent bond between the carbon and oxygen atoms, including a coordinate covalent bond. This type of bond involves two atoms sharing a pair of electrons, with one atom providing both electrons. On the other hand, lithium oxide is an ionic compound, consisting of lithium ions (Li+) and oxide ions (O2-). The ions in lionic compounds are held together by strong ionic bonds in a three-dimensional crystal lattice structure which requires much more energy to break apart, leading to a higher melting point for lithium oxide compared to the molecular solid structure of carbon monoxide.