Hydrocarbons are composed primarily of which two elements?

• A. $C$ and $H$
• B. $C$ and $O$
• C. $O$ and $S$
• D. $H$ and $N$

Answer: (A)

Verified step by step guidance

1. Understand that hydrocarbons are organic compounds consisting entirely of carbon and hydrogen atoms.
2. Recall that the term 'hydrocarbon' itself indicates the presence of hydrogen (H) and carbon (C) elements.
3. Recognize that other elements like oxygen (O), sulfur (S), or nitrogen (N) are not part of the basic hydrocarbon structure but may appear in other organic compounds.
4. Therefore, identify the two primary elements in hydrocarbons as carbon (C) and hydrogen (H).
5. Summarize that hydrocarbons are composed primarily of the elements carbon and hydrogen, which form the backbone and the attached atoms of these molecules.