🧪 Part 1: Identifying Chemical Changes

1. Which of the following is the BEST evidence that a chemical change has occurred?

A change in shape

Formation of a gas (bubbling)

A change in size

Melting of ice

2. In our baking soda and vinegar experiment, which signs of chemical change did you observe? (Check all that apply)

Gas production (bubbling)

Temperature change

Color change

Formation of new substances

3. Which of these examples represents a chemical change?

Tearing a piece of paper

Iron rusting

Water freezing into ice

Breaking a glass bottle

4. The law of conservation of mass states that in a chemical reaction:

Mass is created

Mass is destroyed

Mass stays the same

Mass doubles

✏️ Part 2: Experiment Analysis

5. Describe what happened when baking soda and vinegar were mixed together in today's experiment:

6. Explain why the balloon inflated during the chemical reaction:

7. Fill in the blanks: During a chemical reaction, atoms are _____________ but not created or destroyed. This is why the total _____________ remains the same before and after the reaction.

8. Give one example of a chemical change you might observe in your daily life and explain why it's a chemical change:

🔬 Part 3: Critical Thinking

9. A student claims that when sugar dissolves in water, it's a chemical change because the sugar "disappears." Do you agree or disagree? Explain your reasoning:

10. If you had 10 grams of baking soda and 15 grams of vinegar before the reaction, predict the total mass of all products after the reaction. Explain your answer: