Unit 2 Review

1. The diagram above shows a block from the periodic table. The number six represents the...

• A. atomic mass of the element carbon
• B. atomic number of the element carbon
• C. number of neutrons in the element carbon
• D. number of valence electrons in the element carbon

2. Carol placed a lid over a pot of boiling water. After five minutes, she removed the lid and noticed water drops had formed all over the lid's inner surface. Which statement describes the change in the water vapor molecules as they changed to liquid?

• A. Heat energy at the lid's surface increased.
• B. The water molecules average speed decreased.
• C. The attractive force between the water molecules decreased.
• D. The water molecules average speed increased

3. Using the Law of Conservation of Matter, determine the number of grams of iron sulfide (FeS) that will be produced in this reaction.

• A. 24 grams
• B. 32 grams
• C. 56 grams
• D. 88 grams

4. As you move across the periodic table from left to right within a period, the elements __________

• A. become less stable.
• B. become more reactive.
• C. change from gases to solids.
• D. change from metals to nonmetals.

5. Look carefully at the pictures below. Which picture shows only a physical change in the wood?

• A
• B
• C
• D

6. Mary wants to find the density of a small stone. Which tools will she need?

• A. A meter stick and a thermometer.
• B. A thermometer and a balance.
• C. A balance and a graduated cylinder.
• D. A graduated cylinder and a meter stick

7. If different kinds of atoms are represented by different colored dots, which picture below represents a mixture?

• A
• B
• C
• D

8. How many different types of elements make up a carbon dioxide molecule?

• A. 1
• B. 2
• C. 3
• D. 4

9. What happens to a liquid when it reaches its boiling point and more heat is added?

• A. It stays a liquid.
• B. Its atoms and molecules move faster and it eventually becomes a gas.
• C. It chemically changes into a new substance.
• D. Its atoms and molecules gain enough energy for it to become a solid.

10. The two blocks shown have the same volume. Which one has the greater density?

• A. The one with more mass
• B. The one with more texture
• C. The one with the darker color
• D. The one with the lower melting point