Only do number three please help me

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What is the theoretical yield of carbon dioxide? a)0.993 gb)2.98 gc)3.65 gd)8.93 g

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

The diagram shows the relationship between scientific disciplines.the names of some scientific disciplines have been removed from the boxes. which scientific discipline belongs in the blue box? a.physics b.biology c.chemistry d.metallurgy