An open syllable is a syllable which lacks a coda, that is, which is not closed by a consonant: C0 V or C0 VV. A syllable which is not open is a closed syllable. An open syllable may contain an onset ((an) initial consonant(s)) and it contains a short or long vowel. The rhyme of an open syllable does not branch, it only contains the nucleus (or, alternatively, peak). The English words eye [aɪ], go [goʊ], and schwa [ʃwɑː] exemplify open syllables.
all syllables in the English name A-me-ri-ca are open.