Three students propose hypotheses to explain why a copper coin turns green over time:
* Student 1 believes that the green color is copper carbonate formed when copper reacts with carbon dioxide and water vapor in the air.
* Student 2 believes that the green color is copper chloride formed when copper reacts with airborne chlorine from coastal salt spray.
* Student 3 believes that the green color is copper oxide formed when copper reacts only with gaseous oxygen in dry air.
Match each chemical requirement for the coin turning green to the student who proposes it.
- Requires carbon dioxide and water vapor to form the green compoundStudent 1
- Requires chlorine from coastal salt spray to form the green compoundStudent 2
- Requires only gaseous oxygen in dry air to form the green compoundStudent 3
Answer
Student 1 believes carbon dioxide and water vapor are required. Student 2 believes chlorine from coastal spray is required. Student 3 believes only gaseous oxygen in dry air is required.
Each student's hypothesis specifies a different chemical process and set of reactants needed to produce the green coating on the copper coin. Student 1 claims copper carbonate forms from carbon dioxide and water vapor. Student 2 claims copper chloride forms from coastal chlorine spray. Student 3 claims copper oxide forms from oxygen in dry air.
Step-by-Step Solution
Key Concept
Identifying the specific components, assumptions, or chemical requirements of different scientific hypotheses.