Answer
nm (nanometer)
Work Step by Step
$10^{-9}$ meter equates to 1 nanometer (nm) because the prefix "nano-" means $\frac{1}{1,000,000,000}$ or $10^{-9}$.
Once 1 nanometer is converted to meters, the answer would be $10^{-9}$ meter.
1 nanometer $\times$ $\frac{1 meter}{1,000,000,000 nanometer}$ = 0.000000001 or $10^{-9}$ m.
