Unit 2 Chemical and Nuclear Reactions Assessment

1. What term describes a process in which plants absorb carbon from the atmosphere?

• A. evaporation

• B. photosynthesis

• C. respiration

• D. transpiration

2. What causes water to change state and move continuously through the water cycle?

• A. air pressure

• B. Earth's rotation

• C. energy

• D. gravity

3. Which two stages of the water cycle happen after evaporation?

• A. runoff and precipitation

• B. precipitation and transpiration

• C. condensation and precipitation

• D. condensation and transpiration

4. Which compound contains three times more oxygen atoms than nitrogen atoms?

• A. Al(NO ₂) ₃

• B. Mg(NO ₃) ₂

• C. (NH ₄) ₂CO3

• D. NH ₄NO ₃

5. The diagram of an organic molecule is shown below.

Which chemical formula represents the molecule shown in the diagram?

• A. CH ₄

• B. C ₂H ₆

• C. 2CH ₃

• D. 6CH

6. Which molecule has only single bonds?

• A. N ₂

• B. CO ₂

• C. C ₂H ₄

• D. C ₂H ₆

7. Gloria is building models of compounds with a molecular model kit. The chart below lists the colors of balls that represent different elements in Gloria’s molecular model kit.

Which model pieces are needed to construct a molecule of isopropyl alcohol (C ₃H ₈O)?

• A. 3 yellow, 8 blue, 1 red

• B. 3 red, 8 yellow, 1 blue

• C. 3 red, 1 purple, 8 green

• D. 3 yellow, 1 green, 8 blue

8. A chemistry teacher draws the Lewis structure of carbon dioxide, CO ₂, on the chalkboard. Which of these correctly describes the bonds between carbon and the two oxygens?

• A. Both are single bonds.

• B. Both are double bonds.

• C. One is a triple bond and one is a single bond.

• D. One is a single bond and one is a double bond.

9. A Lewis structure for hydrogen peroxide is shown below.

Which formula represents hydrogen peroxide as shown in the Lewis structure?

• A. 2H ₂O

• B. 2HO ₂

• C. H ₂O ₂

• D. H ₂O ₄

10. Which statement best describes the biological process of photosynthesis?

• A. Light energy is transformed into chemical energy and carbon dioxide is released.

• B. Chemical energy is transformed into light energy and carbon dioxide is released.

• C. Light energy is transformed into chemical energy and oxygen is released.

• D. Chemical energy is transformed into light energy and oxygen is released.