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Utah Science

Curriculum Consortium

Tyson Grover 

tgrover@dsdmail.net

Annette Nielson

afonnesbeck@dsdmail.net

Storyline Narrative 8.1.6

OVERVIEW: Over the next several days the students will be developing and using models to reinforce the idea that in a chemical reaction atoms/matter are conserved and not created nor destroyed. We will be teaching the students about the Law of Conservation of Matter or also known as the law of conservation of mass. It states that for any closed system (no transferring of energy) the mass or matter of the system must remain constant over time, hence the quantity of mass is “conserved”. The only way to change the mass of the system would be to add or remove it.

 

Students experience a phenomenon in which matter appears to be lost when a chemical reaction takes place. They will measure the mass of the reactants, perform the reaction, and measure the mass of the products. Students will ask questions about what they experienced. Students then compare the masses of the reactants and products of several chemical reactions in episode 2. They will decide if any mass was lost and if so, what might have happened to it. Students are introduced to the Law of Conservation of Mass (matter). In this episode three students will review the Law of Conservation of Mass and learn how to recognize if chemical equations follow this law. They will review how to write molecular formulas and will learn how to write a full chemical equation, including how to show the number of molecules involved. In episode four, students will create a model demonstrating that in a chemical reaction, matter is conserved, or the same atoms rearrange to form new molecules, following the Law of Conservation of Mass.


Assessment: The assessment for this standard is the model that the students create in episode 4 to demonstrate the law of conservation of mass. As part of that they should demonstrate that they understand how to read a chemical equation and can recognize if the follows the law of conservation of mass as it is written (if it is balanced).

Episode 1

Question

What happens to mass of reactants during a chemical reaction?

Snapshot

Students experience a phenomenon in which matter appears to be lost when a chemical reaction takes place. They will measure the mass of the reactants, perform the reaction, and measure the mass of the products. Students will ask questions about what they experienced.

Conceptual Understandings

Sometimes it appears that matter is lost during chemical reactions.

Is mass always lost during a chemical reaction?

 

Conceptual Understandings

Students will discover that according to the Law of Conservation of Mass, the mass of reactants should equal the mass of the products of a chemical reaction. In a chemical reaction bonds between atoms break apart and rearrange to create new substances.

What do balanced equations look like with the law of conservation of mass?

Snapshot

Students will compare the masses of the reactants and products of several chemical reactions. They will decide if any mass was lost and if so, what might have happened to it.

Students are introduced to the Law of Conservation of Mass (matter).

Episode 2

Question

What happens to the atoms when a chemical reaction occurs?

 

Episode 3

Question

What do balanced equations look like with the law of conservation of mass? How do we balance equations?

Snapshot

Students will play the PhET Balancing Equations game to learn how and what balanced equations look like.

Conceptual Understandings

Students will discover that balanced chemical equations demonstrate the law of conservation of mass.

Can we create a model to illustrate the Law of Conservation of Mass?

Episode 4

Question

Can we create a model to illustrate the Law of Conservation of Mass?

Snapshot

In this episode, students will create a model demonstrating that in a chemical reaction, matter is conserved, or the same atoms rearrange to form new molecules, following the Law of Conservation of Mass.

Conceptual Understandings

The final assessment for this standard is the model that students create demonstrating the Law of Conservation of Mass during the final episode.