Which of the following is an example of PM composition mentioned?

Which of the following is an example of PM composition mentioned?

• A. Water vapor
• B. Ozone
• C. Combustion particles
• D. Nitrogen gas

Answer: (C)

Particulate matter is made up of tiny solid or liquid particles suspended in air, not gases. Water vapor and ozone are gases, and nitrogen gas is also a gas. Combustion particles are the example that fits PM because they are actual particles produced by burning fuels, such as soot or organic/inorganic aerosols. This distinction is what makes combustion particles the correct choice. In practice, PM composition includes various particles like soot, organic carbon, sulfates, nitrates, dust, and sea salt—all of which are solid or liquid particles rather than gases.

Particulate matter is made up of tiny solid or liquid particles suspended in air, not gases. Water vapor and ozone are gases, and nitrogen gas is also a gas. Combustion particles are the example that fits PM because they are actual particles produced by burning fuels, such as soot or organic/inorganic aerosols. This distinction is what makes combustion particles the correct choice. In practice, PM composition includes various particles like soot, organic carbon, sulfates, nitrates, dust, and sea salt—all of which are solid or liquid particles rather than gases.