Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Number of possible molecular formulae as a function of mass restricted by mass alone (red) or both mass and number of carbons (blue). When restrained by both mass and number of carbons, the number of possible molecular formulae for a given mass is severely restricted. Figure adapted with permission from Stupp et al. (2013).
