Which statement is true about particulate matter?

The statement that particulate matter consists of solid particles including carbon and hydrocarbons is true because particulate matter is a complex mixture of tiny solid particles and liquid droplets that can be found in the air. These particles are composed of various materials, including not just carbon, but also metals, organic compounds, and other substances that can arise from combustion processes, industrial activities, and natural sources like dust or pollen.

This composition means that particulate matter can include a variety of components, such as soot, which is predominantly carbon, as well as unburned hydrocarbons and other chemical compounds. The presence of these diverse materials contributes to the environmental and health effects associated with particulate matter, making it a critical factor in air quality considerations.

While the other statements suggest a more narrow composition that does not accurately reflect the true nature of particulate matter, the correct assertion acknowledges its complexity and broad range of components, reinforcing the importance of understanding its sources and impacts.