D protons. <span>the identity of an element is determined by the total number of protons present in the nucleus of an atom contained in that partial element.
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2 C2H2 + 5 O2 --> 4 CO2 + 2 H2O
2.35 mol C2H2 - x mol O2
2 mol C2H2 - 5 mol O2

answer: 5.875 mol
I think it is B. Earths magnetic feild
But i'm not sure.
Your answer is D, OH-! correct me if I’m wrong.
Is a solid because liquids are not is not that close and gas is very far apart.