How many meters are in a nanometer?

A nanometer is a unit of length in the metric system that is equal to one billionth of a meter. This is represented numerically as (10^{-9}) meters. The nanometer is commonly used in fields such as physics, chemistry, and biology, especially when dealing with atomic and molecular scales, as many atoms and molecules are on the order of nanometers in size.

Understanding the metric prefixes is key here; "nano" specifically denotes a factor of (10^{-9}). This means there are one billion nanometers in one meter, making it the correct conversion factor in this context.