Which toxic chemical is produced by the burning of wood?

The correct answer is that carbon monoxide is a toxic chemical produced by the burning of wood. During combustion, particularly when there is insufficient oxygen, wood does not burn completely, leading to the formation of carbon monoxide, a colorless, odorless gas that can be very harmful when inhaled. It binds to hemoglobin in the blood more effectively than oxygen does, which can result in a reduced ability to carry oxygen throughout the body, potentially leading to suffocation.

Other choices like formaldehyde can also be produced during wood burning, especially when certain types of wood are combusted at lower temperatures, but carbon monoxide is more directly associated with incomplete combustion. Cyanide is typically linked to the combustion of specific materials such as plastics and certain synthetic materials rather than wood itself. Ammonia is generally not a significant product of wood burning either; it is more commonly associated with agricultural processes or certain industrial activities. Therefore, carbon monoxide stands out as the primary toxic byproduct of wood combustion.