Chapter 2 Chemistry

Name: ______Period: ______

Chapter 2 – Chemistry

Section 2-1 Composition of Matter

1. Explain the difference between mass & weight.
2. Why do biologists study chemistry?
3. Name the 4 elements that make up 90% of the mass of living things. Give the symbol for each of these elements.
4. Sketch a block from the periodic table and label the atomic number, atomic mass, & symbol for the element.
5. What is the center of an atom called & what 2 subatomic particles are found there?
6. Where is most of the mass of an atom concentrated?
7. How is the atomic number of an element determined?
8. Explain why the overall or net charge on an atom is zero.
9. How many electrons can these energy levels hold --- a. first? b. second?
10. Define compound and write a formula for water, carbon dioxide, & sodium chloride (table salt).
11. Do compounds have the same chemical properties as the elements that compose them?
12. When would an atom be chemically stable (not react)?
13. What occurs in a chemical reaction?
14. Forming an ionic or a covalent bond helps make atoms more ______.

Section 2-2 Energy

1. All living things require ______to do work.
2. Energy can't be created or ______in a chemical reaction, but it can be ______from one form into another.
3. Name 4 forms of energy important to living things.
4. Give an example of energy changing form in an organism.
5. Atoms & molecules are in constant ______.
6. Name the 3 main states of matter.
7. Explain how the shape and volume of a solid, liquid, and gas differ.
8. Organisms undergo thousands of ______as part of their life processes.
9. Where are the reactants and products in a chemical equation?
10. What does a two-direction arrow mean in a chemical equation?
11. ______are broken down in chemical reactions in your body to release ______and produce ______and ______.
12. What are biological catalysts called?
13. Redox is the abbreviation for what type of reaction?
14. Redox reactions involve the transfer of energy and ______between atoms.

Section 2-3 Solutions

1. Many of the chemical reactions in organisms take place in ______.
2. Name & describe the 2 parts of a solution.
3. What is meant by concentration of the solution?
4. How do you get a saturated solution?
5. What is the hydronium ion?
6. How are acidity and alkalinity measured?
7. What adjective refers to basic solutions?
8. What is the pH scale used for?
9. What is the range for the pH scale?
10. At what pH would you find each of these solutions on a pH scale: a. acids? b. Bases? c. neutral?
11. A change of one pH unit reflects a ______change.
12. Why is controlling the pH range important to organisms?
13. How do organisms control their pH levels?