Answer:
Magnesium hydroxide has 3 unique elements.
Explanation:
Long story short, 2 is the balancing compound in structure to make up hydroxide, therefore 1 compound would be left to create Mg(2O)H.
(This is only an opinion of mathematical science to me, I don't have complete understanding of this subject either, good luck.)
Water is H2O but I'm not sure about solids.
Foods are a solid we need to survive
Vinegar is the only thing listed
Decrease because loss of electrons.
