A 4-week middle school chemistry sequence aligned to MS-PS1-2 using the 5E inquiry model. Students investigate characteristic properties, atomic rearrangement, and macroscopic evidence of chemical reactions through engaging hands-on labs and data analysis.
Evidence Claim: Why does the flammability of the gas prove a new substance was created?
4 Scientific Reasoning Synthesis
A classmate says: "If two substances mix and change temperature or color, atoms disappeared into thin air." Correct this misconception using what you learned about atomic rearrangement:
• Please write your name on Page 1 and place your completed paper into the class turn-in bin for the substitute teacher •
MS-PS1-2 Evidence Investigation • Day 4 Sub-Plan Page 2 of 2
Do not mix dry yet
2
Liquid Cup
Stand 10 mL phenol red cup upright in the center of the bag. Keep it standing!
Zero spills inside cup
3
Airtight Seal
Gently squeeze excess air out of the bag and seal zipper completely shut.
Check zipper twice!
4
Tip & Observe
Tip over the cup from outside the bag. Swirl gently and feel the temperature changes!
Record all 4 senses
Key Question: What evidence proves that brand-new substances formed inside the bag? Record on Lab Handout Page 2
Evidence of a Chemical Reaction
Observable Patterns
01
Temperature Shift
Energy is released (feels hot) or absorbed (feels cold) without an external heat source.
02
Gas Production
Bubbles, foaming, or a bag inflating indicate a brand-new gas formed from liquid/solid reactants.
03
Unexpected Color Change
The final color cannot be explained by simple mixing (e.g. red turning bright yellow or white).
04
Precipitate / New Solid
A solid powder forms when two clear liquids mix, settling to the bottom.
NGSS MS-PS1-2 Evidence Statement 3 Characteristic Properties Must Change!
Distilled Water Odor: Odorless Flammability: Non-flammable Boiling Point: \(100.0^\circ\text{C}\)
Mineral Oil Odor: Mild, faint oily Flammability: Combustible at high heat Boiling Point: \(300+^\circ\text{C}\)
Why is flammability considered a chemical property, while boiling point is a physical property?
5 Mystery Substance Identification Matrix
Using your data from Stations 1 through 4, identify Mystery White Powder #1:
Identity Claim:
Supporting Characteristic Evidence:
Target Check: "I can identify pure substances using characteristic properties regardless of sample size." [ ] Mastered [ ] Practicing
MS-PS1-2 Characteristic Properties • Explore Phase Page 2 of 2
Mass ÷ Volume
2
Solubility Well
Add 1 scoop into water and 1 scoop into oil. Stir for 20 seconds. Does it dissolve?
Clear vs. Cloudy
3
Melting Bath
Observe small samples in an \(80^\circ\text{C}\) water bath. Which substance liquefies first?
Phase Transition
4
Flammability Data
Analyze chemical property evidence cards for alcohol, mineral oil, and water.
Chemical Property
Rotation Reminder: Leave each station clean and dry before rotating to the next table. Record all data in Handout
The Golden Rule of Matter
Core Conceptual Model
Non-Characteristic Properties
Changes with Size
Mass: More stuff = more mass.
Volume: More stuff = takes up more space.
Shape: Cutting, crushing, or pouring changes it.
Cannot be used to identify an unknown substance!
Characteristic Properties
Always Constant
Density: Ratio of mass to volume is fixed.
Melting / Boiling Point: Exact change temp.
Solubility & Flammability: Inherent to substance.
True fingerprints used to solve chemical mysteries!
DCI PS1.A: Structure and Properties of Matter MS-PS1-2 Target
1. Evaporation Test: If we evaporate the water from Scenario A, what substance will be left in the dish? Why?
2. Permanent Property Transformation: Can you scrape the rust off the steel wool and turn it back into shiny, flexible iron metal using only physical cooling or drying? Explain using atomic bonds:
3. Connecting Microscopic to Macroscopic (CCC Patterns): Complete the cause-and-effect chain:
Microscopic Cause: Atoms in reactants break bonds and regroup into new molecules \(\longrightarrow\) Macroscopic Effect: (Describe what scientists observe with their eyes/tools):
Explain & Elaborate Target Self-Check
I can explain that in a chemical reaction, atoms regroup into new molecules with different properties. I can distinguish between physical dissolving (molecules disperse) and chemical reacting (bonds break/reform).
MS-PS1-2 Atomic Rearrangement • Explain Phase Page 2 of 2
Ex: \(\text{NaHCO}_3 + \text{Acid}\)
Step 2: Interaction
Bonds Break
Colliding molecules break existing bonds. Atoms freely rearrange into new groupings.
→ ENERGY SHIFT →
Step 3: Products
Brand-New Bonds
New molecules form with completely different physical and chemical properties.
Tables 1 & 2 completely and accurately filled with pre/post properties.
Data partially recorded; some properties missing.
/ 4
Claim & Evidence
Accurate claim with ≥2 specific characteristic property data points cited.
Claim stated but cites only general observations without data.
/ 4
Scientific Reasoning
Explicitly connects property changes to atomic rearrangement into new molecules.
Mentions a reaction occurred but does not explain atomic rearrangement.
/ 4
MS-PS1-2 Summative Evaluation • Evaluate Phase Page 2 of 2
DAY 19: Conservation Law 2 min
State the Law of Conservation of Mass in your own words:
DAY 20: Unit Reflection 2 min
Which lab investigation best proved that atoms rearrange?
4-Week "I Can" Mastery Self-Tracker Check off each target as mastered
W1: I can record property changes in the Baggie Lab. W2: I can identify substances using density & solubility. W3: I can model how reactant atoms regroup into products. W4: I can write a complete CER verdict using data evidence.
