Question

carbon can cycle within and between the geosphere, atmosphere, hydrosphere, and biosphere in different ways.
the steps in the table outline one possible pathway of an individual carbon atom as it moves through the carbon cycle. match each statement to the step it describes.
carbon moves from the geosphere to the hydrosphere via runoff.
carbon moves from the geosphere to the atmosphere via fossil fuel combustion.
carbon is removed from the atmosphere via rainfall and interacts with the geosphere via chemical weathering.
carbon moves from the geosphere to the atmosphere via volcanic activity.
carbon moves from the hydrosphere to the biosphere, and then to the geosphere via limestone formation.
step 1: humans extract petroleum, refine it into gasoline, and burn it to power vehicle engines, releasing carbon dioxide gas into the air.
step 2: carbon dioxide in the air reacts with water to form carbonic acid, which falls as rain onto rocks. over time, acidic rainwater breaks rocks down, forming calcium ions and bicarbonate ions.
step 3: calcium ions and bicarbonate ions from broken - down rocks are carried into the oceans by rivers.
step 4: marine organisms use calcium ions and bicarbonate ions dissolved in ocean water to build shells, which sink to the ocean floor when the organisms die. over time, these shells mix with sediment and form carbon - rich rock.
step 5: tectonic activity causes magma to form underground. eventually, a buildup of pressure results in a volcanic eruption that releases lava, ash, and gases—including carbon dioxide—into the air.

Explanation:

1. Step 1: The description is about burning fossil fuel (petroleum) to release carbon dioxide, so it matches "Carbon moves from the geosphere to the atmosphere via fossil fuel combustion."
2. Step 2: It describes carbon dioxide in air reacting with water (rain) and interacting with geosphere via chemical weathering, so it matches "Carbon is removed from the atmosphere via rainfall and interacts with the geosphere via chemical weathering."
3. Step 3: Calcium and bicarbonate ions from rocks are carried to oceans (hydrosphere) via runoff, so it matches "Carbon moves from the geosphere to the hydrosphere via runoff."
4. Step 4: Marine organisms (biosphere) use ions from hydrosphere to build shells, which form carbon - rich rock (geosphere) via limestone formation, so it matches "Carbon moves from the hydrosphere to the biosphere, and then to the geosphere via limestone formation."
5. Step 5: Tectonic activity (volcanic activity) releases carbon dioxide from geosphere to atmosphere, so it matches "Carbon moves from the geosphere to the atmosphere via volcanic activity."

Answer:

Step 1: Carbon moves from the geosphere to the atmosphere via fossil fuel combustion.
Step 2: Carbon is removed from the atmosphere via rainfall and interacts with the geosphere via chemical weathering.
Step 3: Carbon moves from the geosphere to the hydrosphere via runoff.
Step 4: Carbon moves from the hydrosphere to the biosphere, and then to the geosphere via limestone formation.
Step 5: Carbon moves from the geosphere to the atmosphere via volcanic activity.