What is soot primarily composed of?

Soot is primarily composed of elemental carbon that is produced during the incomplete combustion of organic materials. During combustion, when there is not enough oxygen, the fuel does not burn completely, resulting in the formation of soot. This soot consists mainly of carbon particles and can also include other compounds, but its primary component is indeed elemental carbon.

Incomplete combustion occurs in various scenarios, such as in house fires, where materials like wood, plastic, or other organic substances do not combust entirely. This leads to the production of visible black carbon particles that accumulate as soot.

The other options focus on different byproducts of combustion. Water vapor is a product of complete combustion where hydrogen in the fuel reacts with oxygen. Mineral deposits in ashes come from the inorganic components of materials burned, such as wood or coal, and gaseous emissions from fires mainly consist of various gases that are released into the air during combustion. Therefore, these do not accurately describe the primary composition of soot.