Question

which sentence describes the movement of matter and energy in the carbon cycle?
a. liquid lava flows from a volcano and cools to form solid volcanic rock.
b. plants take co₂ from the air and use light energy to turn co₂ into sugars.
c. water vapor in the air cools and becomes droplets of liquid that form clouds.
d. rivers flow downhill and move surface water toward the ocean.

Explanation:

To determine the correct answer, we analyze each option:

• Option A: Describes the formation of volcanic rock, which is related to the rock cycle, not the carbon cycle.
• Option B: Plants taking in \( \text{CO}_2 \) (a carbon - containing compound) from the air and using light energy to convert it into sugars (which contain carbon) is a key part of the carbon cycle (photosynthesis). This involves the movement of carbon (matter) and the conversion of light energy into chemical energy in sugars.
• Option C: Describes the water cycle (condensation of water vapor to form clouds), not the carbon cycle.
• Option D: Describes the movement of water in the water cycle (runoff), not the carbon cycle.

Answer:

B. Plants take \( \text{CO}_2 \) from the air and use light energy to turn \( \text{CO}_2 \) into sugars.