A Level Physics Practice Exam

What does the prefix "femto" represent in scientific notation?

1. 10^-9

2. 10^-12

3. 10^-15

4. 10^-18

The correct answer is: 10^-15

The prefix "femto" is used in scientific notation to denote a factor of 10 to the power of negative 15, which is represented as 10^-15. This prefix is commonly used in fields such as physics and chemistry to describe very small quantities, such as distances on the atomic scale or the time intervals involved in certain rapid processes. For example, a femtosecond is one quadrillionth of a second (10^-15 seconds), indicating how incredibly brief certain events can be at the molecular or subatomic level. Understanding such prefixes is crucial in scientific communication, as they help convey very large or small magnitudes succinctly.