Lesson 4 - UNIT 3 - Quiz #1

1. Define the following fundamental substances in nature: atom, element, molecule, compound,
and matter.
2. Diagram the structure of any atom of the instructor's choice between atomic number 1 and 20.
3. Explain the concept of density in words and mathematically.
4. Explain and differentiate between the concepts of physical half-life and biological half-life of
radioactive isotopes.