Hehe, how can it be millimeters? How long is millimeter? At least you should hear micron. . All the pupils in the third grade understand. .

The smallest unit of length is "angstrom", that is, one hundredth (10-8) centimeter.

Later, there appeared a smaller unit of length than Egypt, namely Atomi. 1 atomy is one third of 10 cm (10- 16).