HS-PS2-6: How Molecular Structure Makes Materials Work
Also called NGSS HS-PS2-6 · Topic: Structure and Properties of Matter · Physical Science
The Official Wording
Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.
Clarification statement: Emphasis is on the attractive and repulsive forces that determine the functioning of the material. Examples could include why electrically conductive materials are often made of metal, flexible but durable materials are made up of long chained molecules, and pharmaceuticals are designed to interact with specific receptors.
Assessment boundary: Assessment is limited to provided molecular structures of specific designed materials.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What HS-PS2-6 Means in Plain English
High school students explain to an audience why a designed material behaves the way it does, tracing its usefulness back to the arrangement of its atoms or molecules and the attractive and repulsive forces between them. Examples include metal wires, stretchy polymers and medicines.
Students work from structures they are given rather than working them out on their own. The standard builds on synthetic materials in middle school (MS-PS1-3) and on particle attraction evidence from HS-PS1-3.
HS-PS2-6 I Can Statements
- I can link a material's job to its molecular structure.
- I can explain why metals conduct electricity and plastics do not.
- I can present a clear explanation with a labeled diagram.
HS-PS2-6 Worked Example
A teardown of an old phone charging cable that ends with each group presenting a one-page infographic.
Why does a charging cable have a copper core and a soft plastic coat?
Set It Up: A worn-out charging cable, wire strippers, a multimeter, goggles, and diagrams of metallic and polymer structures.
- Strip the end and separate the thin copper strands from the PVC coating.Bundle of fine copper strands
- Test resistance across a strand and across the coating with the multimeter.Copper near 0 ohms, coating off the scale
- Bend and stretch each part and note what happens.Strands bend, coating stretches and springs back
- Match each behavior to the structure diagrams.Sea of electrons vs long tangled chains
- Build an infographic explaining both parts for a younger audience.One labeled diagram per material
Copper conducted easily while the coating blocked it, and the coating flexed without cracking.
Why it works: In copper, outer electrons move freely among the atoms, while PVC is made of long chain molecules that hold their electrons tightly and can slide and coil.
Common Mistakes with HS-PS2-6
Describing properties without structure
“Copper is used because it conducts well.”
Try this: Say why it conducts: copper atoms share a pool of loose outer electrons that drift through the metal when a voltage pushes them.
Thinking polymers are just big atoms
Drawing plastic as one giant ball
Try this: Draw a polymer as long repeating chains. Their tangling and weak attractions between chains explain the flexibility and toughness.
Forgetting the audience
An infographic full of terms with no definitions
Try this: Define each science word in plain language and pair it with a picture so a reader new to chemistry can follow the explanation.
Where HS-PS2-6 Fits
Practice HS-PS2-6
Quick Check
- Why are electrical wires almost always made of metal?
- What molecular feature makes many plastics flexible?
- Why do drug designers care about a molecule's shape?