It varies greatly, but it's usually 3 - 4 µm (micrometers).
If you mix iodine with a starch, what is the resulting color?
"The only people you should get even with are those who have helped you."
2017: Anatomy and Physiology, Crime Busters, Meteorology, Reach for the Stars, Rocks and Minerals, Write It Do It
2016: Crave the Wave, Crime Busters, Meteorology, Picture This, Reach for the Stars