Smoke

Smoke, dispersion of small liquid or solid particles, usually produced by a combustion process. These particles are usually less than one micrometer, or one-millionth of a meter, in size, so small as not to be individually visible. Larger particles that can be seen singly are generally called dust; dust settles relatively rapidly compared to smoke particles. Smoke from furnaces and industrial plants frequently prompts community complaint and control. See Air Pollution; Smog.