What were the four fundamental substances postulated by the Greeks?
Who was the first scientist generally accredited with putting the study of chemistry on a firm experimental basis?
In addition to his important work on the properties of gases, what other valuable contributions did Robert Boyle make to the development of the study of chemistry?
How many elements are presently known? How many of these elements occur naturally, and how many are synthesized artificially? What are the most common elements present on the earth?
What are the five most abundant elements (by mass) in the earth’s crust, oceans, and atmosphere?
Read the “Chemistry in Focus” segment Trace Elements: Small but Crucial, and answer the following
a. What is meant by the term trace element?
b. Name two essential trace elements in the body and list their function(s).