The distinction between an aerosol and a droplet is size: aerosols are smaller. But the word “droplet” doesn’t mean what it seems to mean. It does not imply a raindrop-sized visible particle, like a mucus ball that a person with a cold might blow into a handkerchief. An average raindrop is about 1/25th of an inch, or 1 millimeter – 1/1000th of a meter. Most people can’t see objects smaller than about 0.1 millimeters without using a magnifying glass or microscope. Viruses, aerosols, and droplets are measured on much smaller scales.
