Final answer:
To classify a compound as ionic or molecular, one must evaluate if it consists of metals and non-metals (ionic) or just non-metals (molecular). Ionic compounds form a crystal lattice and conduct electricity when dissolved, while molecular compounds have lower melting points and do not conduct electricity.
Step-by-step explanation:
To classify each compound as ionic or molecular, one should understand the characteristics and bonding of each type of compound. Ionic compounds consist of a metal and a non-metal where there is a transfer of electrons from one atom to another, leading to the formation of ions. These ions group together in a crystal lattice structure. Ionic compounds typically have high melting points and conduct electricity when dissolved in water or melted.
Molecular compounds, also known as covalent compounds, are formed when two non-metals share electrons, resulting in the formation of molecules. The atoms within a molecule are held together by covalent bonds. Molecular compounds usually have lower melting points than ionic compounds and do not conduct electricity in solid or dissolved states.
When deciding whether a compound is ionic or molecular, one should look at the elements present in the compound. A compound with a metal and a non-metal is often ionic, whereas a compound with only non-metals is more likely to be molecular.