Nanometre (nm)

For a comparison, state both the relative size and supporting figures, for example: “a typical atom is about $0.1\ \text{nm}$, whereas nanoparticles are about $1$–$100\ \text{nm}$.”

Use the whole nanoparticle range: a particle between 1 nm and 100 nm is on the nanoscale.

Write $1\,\text{nm}=1\times10^{-9}\,\text{m}$ before converting; this helps prevent errors with zeros or powers of ten.