What is the prefix for a factor of 10^-15?

The prefix for a factor of 10^-15 is "femto." This prefix is derived from the Danish word "femten," which means fifteen. In the International System of Units (SI), "femto" is recognized specifically for this magnitude, making it a standard unit when expressing very small quantities, such as in the context of science and engineering.

For context, "pico" represents a factor of 10^-12, "milli" represents 10^-3, and "nano" denotes 10^-9. Understanding these prefixes is essential as they allow scientists and engineers to effectively communicate measurements across vastly different scales, particularly in fields such as physics, chemistry, and nanotechnology.