Since we are talking about detecting the melting point of our compound, we will then assume with reasonable basis that our compound is a solid. Another way to verify the identity of the compound is by determining its density. We can separately measure the sample's mass and then measure its volume through, maybe, water displacement methods. we can use density as our defining factor here because density is a unique property to each element and compound.

We can divide the measured mass by the measured volume to get the density of the compound, and apply necessary calculations to determine the margins of error. If the percentage error is reasonably small, then we can thus use the density as a definitive proof of the substance's identity.