Sarah and Maria mixed some iron filings with yellow sulfur powder. Both iron and sulfur are elements in the periodic table. The girls used a magnet to separate the iron filings from the sulphur. Next, the girls poured the two elements in a test tube and heated the mixture in a flame. The two elements melted and black smoke came out of the test tube. The two liquids seemed to combine. When the girls stopped heating the test tube, there was a shiny black solid inside. The took a magnet and held it up to the new substance but nothing happened. Why?
The solid, iron sulfide, had new properties. The girls caused a synthesis reaction. Something new, a compound iron sulfide, was formed. It has properties different form its parts.