There is no single route to answering a question or explaining an observation, and describe or predict some facet of the natural world. What does this question means? I don't understand it.

What does earth, air, fire, and water have to do in chemistry? Chinese and The Eastern Mediterranean and Egypt person have transform "base metals" such as lead and "noble metals" like gold to create cures for there people. How did them do that, what was there evolution to make this cure for there people work? How is it possible to create a cure with lead and gold? What were the chemicals they used? Why does everything revolves around Chemistry? Why people put Chemistry first and not Biology?