Question

olivia observes bubbles while boiling water and concludes that this is a chemical change. do you agree or disagree with olivia? i agree, because the water vapor can be changed back to liquid water. i disagree, because bubbles are usually a sign of physical change. i agree, because increasing the temperature causes the change to occur more quickly. i disagree, because the water molecules do not change.

Explanation:

Step1: Define chemical and physical change

A chemical change results in new substances with different chemical properties, while a physical change only changes the state or form of a substance without altering its chemical composition.

Step2: Analyze boiling water

When water boils, it changes from liquid to gas (water - vapor). The chemical formula of water remains H₂O throughout the process. There is no new substance formed, just a change in state.

Step3: Evaluate options

• Option 1: Just because water - vapor can be changed back to liquid water does not mean it's a chemical change. This is a characteristic of a physical change.
• Option 2: Bubbles during boiling are a sign of a phase change (liquid to gas), which is a physical change, but the reasoning is not the best.
• Option 3: Increasing temperature affects the rate of the change, but it doesn't determine whether it's a chemical or physical change.
• Option 4: Since the water molecules do not change (still H₂O), boiling water is a physical change, not a chemical change.

Answer:

I disagree, because the water molecules do not change.