Yes, HES is a Scrabble word!

Letter values in Scrabble US: H 4, E 1, S 1.

Is it a valid word?

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

a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
the 5th letter of the Hebrew alphabet

Also: atomic number 2.