Class started with a brief review of the definition of elements and of the atom. Examples of molecules, like water, along with the formula were written and a definition derived for a molecule. In the lab, the elements iron, sulfur, and copper were examined and their physical properties outlined. These included color, texture, state, and smell. A combination of sulfur and copper was mixed, and heated in a crucible. The reaction was noted and the product examined. It was determined that the product was not like either sulfur or copper, but had new properties. The definition of a compound was derived from the experimental results.