Answer:
m = 20.9 g.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to solve this problem by recalling both the Avogadro's number for the calculation of the moles in the given molecules of calcium phosphate and the molar mass of this compound in order to secondly calculate the mass as shown on the following setup:

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Nuclei may be unstable if they have
a too much energy.
b too many protons.
C an unstable ratio of protons to neutrons.
d any of the above.
The answer would be, D any of the above.
Hope this helps
Cells and microorganisms are extremely complex
The reagent which limits the reaction is called limiting reagents.
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For example:- N2+3H2gives 2NH3.so here nitrogen limits the reaction.