# The diameter of an atom is approximately 1*10^-8cm . What Is this diameter when expressed in nanometers?

A nanometer is ${10}^{-} 9$ meters.
If you convert $1$ cm into ${10}^{-} 2$ meters, then ${10}^{-} 8 \left({10}^{-} 2\right)$ meters would become ${10}^{-} 10$ meters, and ${10}^{-} 10$ meters converted to nanometers (times ${10}^{9}$) would be $0.1$ nanometers.