1.9. Scope of Chemistry http://www.ck12.org
1.9 Scope of Chemistry
- Define chemistry.
- Give examples of chemistry in everyday life.
The Statue of Liberty, pictured above, is an icon of America and freedom. The statue is made of steel and covered
with a thin layer of copper, the same type of matter that pennies are made of. Copper is a brownish red metal, so
why is the statue green? Chemistry, which is a branch of physical science, has the answer.
What Is Chemistry?
Chemistryis the study of matter and energy and how they interact, mainly at the level of atoms and molecules.
Basic concepts in chemistry include chemicals, which are specific types of matter, and chemical reactions. In a
chemical reaction, atoms or molecules of certain types of matter combine chemically to form other types of matter.
All chemical reactions involve energy.
Q:How do you think chemistry explains why the copper on the Statue of Liberty is green instead of brownish red?
A:The copper has become tarnished. The tarnish—also called patina—is a compound called copper carbonate,
which is green. Copper carbonate forms when copper undergoes a chemical reaction with carbon dioxide in moist
air. The green patina that forms on copper actually preserves the underlying metal. That’s why it’s not removed from
the statue. Some people also think that the patina looks attractive.