In the bunsen burner, the gas and air inlet can be regulated manually. In the case of metals (such as lithium and sodium in this case) they contain an electron in the latter in its external electronic configuration. They are characterized by transferring electrons easily and produce the emission of light when excited, producing flames of different colors in the lighter (orange for sodium and red / scarlet for lithium)
The answer is a compound because it is only a compound that can be broken to elements. for eg. H2o is a compound and be broken to element of 2 molecules of hydrogen and oxygen
