Final answer:
The periodic table can be used to determine whether a formula represents a molecular compound or an ionic compound. Metals and nonmetals have distinct properties that can be used to differentiate them. Semi-metals, or metalloids, have properties intermediate between those of metals and nonmetals.
Step-by-step explanation:
The periodic table can be used to determine whether a formula represents a molecular compound or an ionic compound.
Molecular compounds form between nonmetals and nonmetals, while ionic compounds form between metals and nonmetals.
Metals can be identified by their luster, ability to conduct electricity, and malleability, while nonmetals are typically dull, poor conductors of electricity, and brittle.
Semi-metals, also known as metalloids, exhibit properties intermediate between metals and nonmetals.