Simple tests to identify elements, mixtures, and compounds?

Question

I have four crystaline solids, and I need a range of simple tests such as ph scale, flammability....to identify which are elements, compounds or mixtures.

Answer 1

First, take small amount of each sample to heat up very slowly, such as in an oil bath. The crystaline solid of either an element or a single compound must have a single melting point. A mixture must have multiple melting points for its composition compounds. Thus smples melted at different melting points must be a mixture.
Second, under the protestion of an innert gas such as Helium or Argon (to avoid chemical reaction with O2 at a high temperature), heat up each pure sample (not mixtures) to a very high temperature and cool down. A compound oftentimes decomposes and thus change color or weight. The best way to tell element from a compound is to use Time Of Flight Mass Spectrometer, to check if the sample contains only one element or multiple elements.