Yes, NITROGENS is a Scrabble word!

Letter values in Scrabble US: N 1, I 1, T 1, R 1, O 1, G 2, E 1, N 1, S 1.

Is it a valid word?

NITROGENS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues

Also: n, atomic number 7.