Yes, SCHISMS is a Scrabble word!

Letter values in Scrabble US: S 1, C 3, H 4, I 1, S 1, M 3, S 1.

Is it a valid word?

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

division of a group into opposing factions
the formal separation of a church into two churches or the withdrawal of one group over doctrinal differences