The first syllable is open.
Climax has a closed syllable structure. The final "x" creates a closed syllable with the short "i" sound and the "k" sound being consecutive consonants.
human is a closed syllable word
Photo is an open syllable word.
It is an open syllable.
First syllable closed, second syllable open.
Closed
Closed
The second syllable is open, the first is closed.
Paper is a closed syllable word.
Both open syllables.
Both closed.
It is a closed syllable.
It's a closed syllable.