What do you predict will happen to the mass of the glow-stick as the reaction continues?

What will you investigate in this activity?

How do you think the numbers of atoms before a reaction will compare to the numbers after the reaction?

What pattern did you notice when analyzing the chemical reactions? How did the number of each type of atom before the reaction compare to the number of each type of atom after the reaction?

In a chemical reaction, matter is conserved. This means that no new atoms are made and no atoms are destroyed. Explain how your observations of the chemical reactions in this activity support this idea.

1. In your own words, what did you notice about the total mass of reactants compared to the total mass of products in the Virtual Lab?

2. A reaction starts with 45 g and 132 g of reactants. The products are 24 g, 73 g, and one unknown. What is the mass of the missing product?

Exit Ticket – Law of Conservation of Mass

1. What happened to the total mass in the Virtual Lab?
☐ Increased  ☐ Decreased  ☐ Stayed the same

2. Explain why you think that happened.
Sentence starter: The mass stayed the ______because_____

3a. Total mass of the reactants = 45 g + 132 g = ____ g
3b. Total mass of the known products = 24 g + 73 g = ____ g
3c. Missing product mass = Reactants − Products = ____ g