title: Interstellar matter and chemical evolution.
abstract: The determination of chemical abundances of the interstellar medium is related to three different areas of astronomy: pregalactic conditions, stellar evolution, and chemical evolution of galaxies. The observed abundances permit the testing of theories associated with these areas. Knowledge of the abundances of helium, carbon, nitrogen, and neon relative to the abundance of hydrogen in the interstellar medium puts limits on current models of cosmology, stellar evolution, and galactic evolution.
authors.forename: M
authors.initials: M
authors.lastname: Peimbert
authors.forename: A
authors.initials: A
authors.lastname: Serrano
authors.forename: S
authors.initials: S
authors.lastname: Torres-Peimbert