<em>Answer: In dehydration synthesis reactions, a water molecule is formed as a result of generating a covalent bond between two monomeric components in a larger polymer. In hydrolysis reactions, a water molecule is consumed as a result of breaking the covalent bond holding together two components of a polymer.</em>
Well there's Water, Earth, Fire, and Air. Not quite sure how this would be a school question. But here it is.
6 I think but I might be wrong