A fire deprived of oxygen will produce charcoal, which is black, flammable, and composed mostly of the element carbon. A fire which has some air may produce a mixture of ashes and charcoal, but these are easily separated. Charcoal is insoluble in water and because the air pockets present in the wood are preserved in the charcoal, lumps of charcoal float to the surface of water. By contrast, some components of ash dissolve in water, while the others sink to the bottom. These properties will be exploited in the potash project.
Fire is an exceedingly complex and fascinating phenomenon.
Some chemists' entire careers are devoted to the study of flames. But for now these questions must remain for us deeply mysterious. For now, lets move on to some practical work with fire, our most important technological tool. The fire quiz consist of three questions on any of the following topics discussed in this page. Classify a given substance as heterogeneous or homogeneous.