Answer:
The correct answer is C. element
Explanation:
The sample cannot be an element because an element - or <em>elemental substance</em> - cannot be decomposed into simpler substances. Thus, it cannot be composed by differents types of atoms. For example, an element is carbon (C).
As the sample contains <u>three types of atoms</u>, it can be a compound, a molecule or a mixture, because they can be composed by different types of atoms - of different chemical elements. For example, the sample could contain the element carbon (C) combined with other elements, for example oxygen (O) or hydrogen (H), amoing others.
What do you need to know how to do
The ionic equation will be:
<span>Mg2+(aq) + 2OH-(aq) + 2H+(aq) + 2NO3-(aq) → Mg2+(aq) + 2NO3-(aq) + 2H2O(l)
</span>And the net ionic:
<span>2OH-(aq) + 2H+(aq) → 2H2O(l)
</span>a Balanced equation would be:
<span>Mg(OH)2(aq) + 2HNO3(aq) → Mg(NO3)2 (aq) + 2H2O(l)
</span>Now thsi si so because of the standard equation which is base plus acid=Salt plus water. We need to have in mindo that Mg(OH)2 is sparingly soluble in water and is aqueous mos of the times
3Mg + N₂= Mg₃N₂
n(Mg)=12,2g÷24,4g/mol=0,5mol-limiting reagentn
(N₂)=5,16g÷28g/mol=0,18mol
n(Mg₃N₂):n(Mg)=1:3, n(Mg₃N₂)=0,166mol, m(Mg₃N₂)=0,166·101,2=16,8g.
%(N)= 2·Ar(N)÷Mr(Mg₃N₂) = 2·14÷101,2=27,66%=0,2766
%(Mg) = 3·Ar(Mg)÷Mr(Mg₃N₂)= 3·24,4÷101,2=72,34% or 100% - 27,66%= 72,34%.
