When humans burn fossil fuels, most of the carbon quickly enters the
as carbon dioxide.
•hydrosphere
•atmosphere
•geosphere
•biosphere

Atmosphere.

Explanation:

Carbon moves from fossil fuels to the atmosphere when fuels are burned. When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas.

D) 89.7%

Explanation:

Divide the theoretical yield by the actual yield:

2.80 g / 3.12 g = 0.897

0.897 x 100% = 89.7%