 If we heat a sample of lithium metal, we see that the metal melts quickly. Group 1 metals have a relatively low melting point. As we continue to heat the metal, the lithium reacts rapidly with the oxygen in the air. Lithium oxide and lithium nitride are formed. The smoke that we see is actually the compound. If we let a little bit of the smoke be pulled into the flame, we get the characteristic flame test for lithium compounds, which is a characteristic crimson color.