text: Along with five ammonia ligands, this molecule is bonded to a ruthenium(II)
full_question: Along with five ammonia ligands, this molecule is bonded to a ruthenium(II) [two] metal center in a new complex prepared by Allen and Senoff in 1965. As a ligand, this molecule exhibits weak sigma-donation and strong pi backbonding. When silver(I) [one] oxide is added, this gas is evolved in the Arndt-Eistert homologation of carboxylic acids. When ketones are used as the starting product for the Schmidt reaction, this gas is evolved. This gas is also released as a byproduct of the Sandmeyer reactions. In plants, it binds to a molybdenum-containing enzyme. This gas can be produced by just heating diazonium salts or azides. This gas is often used as an alternative to argon for the creation of inert atmospheres. For 10 points, name this most common gas in Earth's atmosphere.
first_sentence: Along with five ammonia ligands, this molecule is bonded to a ruthenium(II)
raw_answer: dinitrogen gas [or N2]