Yes, TANGELOS is a Scrabble word!

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

Is it a valid word?

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

hybrid between grapefruit and mandarin orange; cultivated especially in Florida
large sweet juicy hybrid between tangerine and grapefruit having a thick wrinkled skin

Also: tangelo tree, ugli fruit, citrus tangelo.

Not playable in Scrabble US: UGLI.