Atoms, Molecules, and Reactions

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Objective

I can build a model to show that the number of atoms stays the same during a chemical reaction, so mass is conserved.

Part 1 of 3

Warm-up video

Unknown Channel · 5:00

We don't generate video — this one is by Unknown Channel on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.

Part 2 of 3

Practice

7 questions

1

Explain the difference between a physical change and a chemical change, providing an example of each that was NOT mentioned in the video.

2

Describe a scenario where a substance undergoes a change in state (e.g., solid to liquid) and explain why this is a physical change.

Part 3 of 3

Exit ticket

Quick comprehension check

If you start with 2 atoms of hydrogen (H) and 1 atom of oxygen (O), and they react to form water (H₂O), how many atoms of hydrogen and oxygen are in the water molecule? In the reaction CH₄ + 2O₂ → CO₂ + 2H₂O, how many carbon (C) atoms are there on the left side of the equation (reactants)? How many carbon atoms are there on the right side of the equation (products)?

Sample answer included in the free materials

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