## Conceptual Physics (12th Edition)

In the metric system, the prefix "M", "mega", means 1 million, so $1 MeV = 10^{6} eV = 1,000,000 eV$. In the metric system, the prefix "G", "giga", means 1 billion, so $1 GeV = 10^{9} eV = 1,000,000,000 eV$.