Daily Archives: May 21, 2015

Oxygen Facts — Get interesting oxygen facts. Discover chemical and physical data and general information and history of the element with atomic number 8.

Oxygen Facts – Atomic Number 8 or O

This entry was posted on May 21, 2015 by Todd Helmenstine (updated on September 6, 2025)

Nitrogen Facts — Get nitrogen facts. Discover the history, chemical and physical properties, and uses of the element with atomic number 7 and symbol N.

Nitrogen Facts – Element Number 7 or N Recently updated !

This entry was posted on May 21, 2015 by Todd Helmenstine (updated on August 22, 2026)