Yes, ARCHANGEL is a Scrabble word!

Letter values in Scrabble US: A 1, R 1, C 3, H 4, A 1, N 1, G 2, E 1, L 1.

Is it a valid word?

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

an angel ranked above the highest rank in the celestial hierarchy
a biennial cultivated herb; its stems are candied and eaten and its roots are used medicinally

Also: garden angelica, angelica archangelica.