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.)
Barrier islands typically have sand in the beach zone and dune field, and mud in the back-barrier. Overwash deposits sand in the back-barrier.
Barrier islands form in three ways. They can form from spits, from drowned dune ridges or from sand bars. Longshore drift is the movement of sand parallel to the shore caused by the angle of the waves breaking on the beach. ... When a storm such as a hurricane digs an inlet through the spit a barrier island is formed.
Each isotope of Oxygen has a different number of neutrons
<h3>Further explanation
</h3>
The elements in nature have several types of isotopes
Atomic mass is the average atomic mass of all its isotopes
Isotopes are atoms has the same number of protons but has a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Some of the isotopes of oxygen are:

Each isotope has 8 protons and 8 electrons but has a different number of neutrons
For O-16: number of neutrons = 16-8 = 8
For O-17: number of neutrons = 17-8 = 9
For O-18: number of neutrons = 18-8 = 10
I think you can only have 3 water molecules because you need 2 hydrogen molecules in every water molecule and you have 6 hydrogen molecules so 6/2=3 and the reactant that is limited would be hydrogen since it limits the amount of water molecules you can have
How many moles of oxygen atoms are present in 5
moles of Mg3(PO4)2
All you have to do is to create
a ratio between the molecule and the oxygen atom.
5 moles of Mg3(PO4)2 (4x2 moles
O/1 mole Mg3(PO4)2) = 40 moles of oxygen