Explain how fossils and other materials can tell us about the conditions of an area at the time it existed.

What are the percent by mass of copper in penny lab

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.

What are the major types of a chemical compound