The relative atomic masses of elements are proportional measures. For example, the Ar for helium is 4.0, and the A r for carbon is 12.0. This means that carbon atoms have three times the mass of ...

Lora is a freelance contributor to Newsweek’s Vault team, specializing in articles on saving, investing, borrowing and making money. Lora has a master’s degree in library science, and is based in ...