South Dakota Science HS-PS2-6

ScienceGrades 9–12Physical Science

The Standard

Communicate scientific and technical information about why the molecular-level structure (intermolecular forces) is important in the functioning of designed materials. (SEP: 8; DCI: PS1.A, PS2.B, ETS1.A; CCC: Structure/Function) Alignment may include HS-ETS1-1

South Dakota Science Standards (2024) · Motion and Stability: Forces and Interactions

Teacher's field guide

What This Standard Means

What Students Need to Do: Students explain how attractions between molecules help a designed material do its job. They use observations and molecular sketches to explain why a wax coating makes paper resist water.
What Mastery Looks Like: Given photos of water on wax paper and clean glass, students explain why the water beads on one surface and spreads on the other. They connect the difference in molecular attraction to the coating's purpose.
Common Misconceptions: Students may say wax pushes water away or has no attraction to water at all. They may confuse attractions between molecules with the bonds holding atoms together within a molecule.
How to Assess It: Show photos of water beading on wax paper and spreading on clean glass. Ask students to explain why the wax coating helps keep a wrapper dry, using one observation and the word "attraction."

Lesson moves

Ways to Teach It

Give pairs a dropper, water, wax paper, and clean glass; have them compare droplet shapes and sketch the attractions at each surface.
Ask students to write two sentences explaining why water beads on wax paper but spreads on clean glass.
Give pairs cards showing water molecules, a polar glass surface, and nonpolar wax; have them match each surface to a droplet photo.
Show a wax-coated sandwich wrapper and a paper bag; ask which would better protect a damp sandwich and why.

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