Smoke is a mixture of small particles and gases that are released when materials burn. The composition of smoke depends on the material that is burning, but in general, smoke consists of solid or liquid particles dispersed in gas.
When materials burn, they release gases such as carbon monoxide, carbon dioxide, and nitrogen oxides. These gases mix with air and can form small particles, which become suspended in the air as smoke. The particles in smoke can be very small, often less than 1 micron in diameter, and can be inhaled deep into the lungs, which can be harmful to human health.
Therefore, the correct option is "solid or liquid particles dispersed in gas." Smoke can contain a variety of particles, including ash, soot, and other chemicals, depending on what is being burned.