nanometer
The millimeter.
0.1 meter is 1 decimeter.
A nanounit means one-billionth of the same unit. (10-9) 1 nanometer = 1 billionth of a meter 1 nanogram = 1 billionth of a gram etc.
An AU. An AU is about 150,000,000 kilometers, while a nanometer is 1 billionth of a meter.
Viruses are measured in nanometers (nm) a billionth of a meter. Viruses range inside from 20 to 40 mm Viruses are measured in nanometers (nm) a billionth of a meter. Viruses range inside from 20 to 40 mm
nm. A nanometer represents 10 ^ -9 or one billionth of a meter.
centigram
decigram
Depending how small it is, you could use the meter, the millimeter, the micron (= micrometer), the nanometer, etc. The meter is approximately the height of a child; the millimeter is 1/1000 of that, the micron is a millionth of a meter, the nanometer is a billionth of a meter.
There is no such unit as a billisecond. A billionth of a second (10-9 s) is called a nanosecond.
I guess it is angstrom unit. The angstromis a unit of length equal to 1/10,000,000,000 (one ten billionth) of a meter (1×10−10 m). The unit was named after the Swedish physicist Anders Jonas Ångström
Microgram