Oklahoma Science 7.PS1.1

Science7th GradeMatter and Its Interaction

The Standard

Develop and use models to describe the atomic composition of simple molecules and extended structures.

Oklahoma Academic Standards for Science (2026)

Teacher's field guide

What Students Need to Do: Students build and read models that show which atoms make up a molecule and how many of each are present. They also model a structure made of a repeating pattern, such as a salt crystal.
What Mastery Looks Like: A student can draw water with two hydrogen atoms joined to one oxygen atom and use the drawing to explain H₂O. They can show a small section of a salt crystal and explain that its pattern continues beyond the drawing.
Common Misconceptions: Students may read the 2 in H₂O as two water molecules instead of two hydrogen atoms. They may draw a salt crystal as separate NaCl molecules rather than a repeating pattern of sodium and chloride ions.
How to Assess It: Ask students to draw one water molecule and a small section of a salt crystal. Have them label each part and write one sentence explaining what repeats in the crystal.

Lesson moves

Give students two colors of beads to build water molecules, then two colors of tiles to extend a salt crystal pattern.
Show drawings of water and a salt crystal, then ask: What does each model show that a chemical formula cannot?
Give pairs formula cards for H₂O and CO₂, and have them race to build each molecule with labeled counters.
Show a diagram of carbon atoms in pencil graphite, and ask students to trace a pattern that repeats across the layer.

Free download

A ready-to-print activity worksheet aligned to 7.PS1.1, with an answer key for the teacher on its own page. No account needed.

PDF, US Letter, prints cleanly in black and white.

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