Is beak a open syllable

Yes, "beak" is an open syllable because it ends with a vowel sound. In linguistics, an open syllable is one that ends in a vowel sound, such as in the Word "beak" where the vowel sound /iː/ is not followed by a consonant. This contrasts with a closed syllable, where the vowel is followed by a consonant, such as in the Word "back."