Question

1. carbon dioxide (co₂) is carbon hooked up with what other element? b. oxygen c. carbon d. hydrogen a. dioxide

Explanation:

Carbon dioxide ($CO_2$) is a compound. In the chemical formula $CO_2$, $C$ represents carbon and $O$ represents oxygen. The subscript 2 indicates that there are two oxygen atoms combined with one carbon atom. So carbon dioxide is carbon combined with oxygen. Option A, dioxide is not an element (it is a part of the compound name indicating two oxygen atoms). Option C, carbon is already in the formula as the first element and the question is about the "other" element. Option D, hydrogen ($H$) is not present in the $CO_2$ formula.

Answer:

B. Oxygen