MS: NGSS - Unit: Chemical Reactions & Conservation of Matter

Chemical Reaction & Conservation of Matter: Complete NGSS Unit (MS-PS1-2 & MS-PS1-5)

How can we tell when a chemical reaction has happened, and what happens to the atoms and the mass when substances react? This 11-lesson, hands-on unit for grades 6–8 helps students answer that question with real data, physical models, and a balance.

Students start by identifying mystery substances by their characteristic properties and measuring density. They then compare property data before and after substances interact to decide whether a chemical reaction occurred, using burning sugar, burning steel wool, soap making, and zinc with hydrochloric acid. Next, they build molecules and model how atoms regroup in a reaction, counting every atom before and after. Finally, they measure mass in closed and open systems with sealed bags, fizzing tablets, burning steel wool, rusting, and elephant toothpaste. Along the way they discover that matter is never created or destroyed, even when mass seems to disappear or appear. The unit ends with a performance task in which students investigate one reaction from start to finish.

What's Included

• Read Me First guide with pacing, a lesson overview, and a whole-unit materials list
• 28-page Teacher Guide with a unit storyline, standards alignment, routines and safety, and a two-page plan for every lesson: lesson flow, expected results, key science for the teacher, common misconceptions, a differentiation menu (ELL/multilingual, neurodivergent, honors/gifted), and the exit ticket
• Student Notes for Lessons 1–10, including printable Reaction Data Cards
• Lesson 11 Performance Task with three Reaction Data Sheets and a 32-point rubric
• 10 exit tickets (3 per page) and a 60-point End-of-Unit Assessment
• Complete answer keys for the student notes, exit tickets (with sample responses at three levels), and the assessment

Lessons

1. Characteristic Properties
2. Density as a Characteristic Property
3. Physical & Chemical Changes
4. Analyzing Reaction Data
5. Atoms, Molecules & Substances
6. Modeling Chemical Reactions
7. Conservation of Mass in a Closed System
8. Open & Closed Systems
9. Burning & Rusting
10. Putting It Together: Elephant Toothpaste
11. Performance Task: Reaction Investigator

Every lesson stays within the NGSS assessment boundaries. Students analyze only density, melting point, boiling point, solubility, flammability, and odor, and they model reactions with pictures and atom counts instead of balancing equations.

Pair It With the Mass Conservation & Atom Modeling Bonus Lab Bundle

For the most complete experience, pair this unit with the four bonus labs in this bundle. Each lab is aligned to MS-PS1-2 and MS-PS1-5, uses inexpensive materials, and does not repeat any activity from the unit. Each one comes with a Teacher Guide, Student Lab Sheet, and Answer Key with CER examples at three levels.

• Making Chalk from Two Clear Liquids: two clear solutions form a solid, and mass is conserved even in an open cup. Fits after Lesson 7.
• Copper Plating a Nail: students trace copper atoms from a penny, into a liquid, and onto a steel nail. Fits after Lesson 6.
• Plaster of Paris: Where Did the Water Go?: water seems to vanish into a hardening solid, but its mass does not. Fits after Lesson 9.
• Splitting Water with Electricity: students collect hydrogen and oxygen and connect a 2-to-1 gas pattern to the atom model. Fits after Lesson 6 or 10.

Together, the unit and labs give students many chances to see the same big idea from different angles: substances react in characteristic ways, atoms regroup, and matter is always conserved.

Terms of Use

This purchase is for single-classroom use only. Please do not share, post, or distribute this resource. If colleagues would like to use it, additional licenses are available at a discount. See the included Terms of Use for full details.

Questions or Concerns?

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