Which gas is most likely to increase as a result of burning fossil fuels?

The increase in carbon dioxide (CO2) as a result of burning fossil fuels is primarily due to the chemical reactions that occur during combustion. Fossil fuels such as coal, oil, and natural gas are carbon-rich materials. When these fuels are burned, they react with oxygen from the atmosphere to release energy, producing carbon dioxide and water vapor as byproducts.

The process can be summarized in a general equation: hydrocarbons (the main components of fossil fuels) react with oxygen to produce carbon dioxide and water. For instance, burning methane (the main component of natural gas) in oxygen results in carbon dioxide and water.

As fossil fuel consumption rises, particularly in power plants, automobiles, and industrial processes, the amount of carbon dioxide emitted into the atmosphere increases significantly. This rise in carbon dioxide is a significant contributor to the greenhouse effect and is linked to climate change, highlighting the environmental impacts of fossil fuel use.

The other gases listed, such as oxygen and nitrogen, are not produced in excess during the combustion of fossil fuels; instead, oxygen is consumed in the reaction. Helium, being an inert gas with no role in combustion processes, does not increase due to fossil fuel burning either. Thus, carbon dioxide is the correct answer, as it