I don't have a calculator with me right now, but that mass would be 1200 grams. Divide the given amount of grams by the molar mass of NH3, which is 17.031g/mol. (Nitrogen + 3(hydrogen)). Again, sorry I didn't have a calculator. But all you would need to do is divide 1200 by 17.031. If you need to use sig figs, your answer should have 2 because the 1.2 x 10^3 limits your amount of sig figs.
Answer : The chemical formula for the compound is, 
Explanation :
When the element 'M' react with the 
to give .
The balanced chemical reaction is,
In this reaction, 'M' is in mono-atomic form and is in diatomic form.
By the stoichiometry,
2 moles 'M' react with the 1 mole of to give 2 moles of .
Therefore, the chemical formula of the compound is,
Yes that is correct because hypotheses should be testable meaning it can be proven wrong and it has to be reasonable meaning it should make sense.
Answer:
phosphorus.
Explanation:
The atomic number of phosphorus is 15 so the protons will be 15.
At the end of the reaction, the catalyst is UNCHANGED.
:)
