1. When a candle burns, which two substances primarily react with each other during the combustion process?

• A. Wax (hydrocarbon) and carbon dioxide
• B. Wax (hydrocarbon) and nitrogen
• C. Wax (hydrocarbon) and water vapor
• D. Wax (hydrocarbon) and oxygen

Answer: (D)

Verified step by step guidance

1. Understand that combustion is a chemical reaction where a substance reacts with oxygen to produce heat and light.
2. Recognize that candle wax is primarily composed of hydrocarbons, which are molecules made of carbon and hydrogen atoms.
3. Recall that during combustion, hydrocarbons react with oxygen (O\_2) from the air to form carbon dioxide (CO\_2) and water (H\_2O).
4. Identify that the two primary reactants in the combustion of candle wax are the hydrocarbon (wax) and oxygen (O\_2).
5. Conclude that the correct substances reacting during candle combustion are wax (hydrocarbon) and oxygen, not carbon dioxide, nitrogen, or water vapor.