Unit Plan 2 (Grade 5 Science): Particles Too Small to See

Focus: Model matter as made of tiny particles that are too small to be seen directly, and use this model to explain everyday phenomena like dissolving, mixing, gases, and smells spreading.

Grade Level: 5

Subject Area: Science (Physical Science • Matter & Models)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

In this unit, students build a particle model of matter to explain how substances can disappear, spread out, or compress even though their matter is still present. Through hands-on investigations and diagrams, students explore how solids, liquids, and gases can all be thought of as collections of tiny particles in motion. They use the model to make sense of phenomena such as sugar dissolving in water, air in a syringe, and a smell traveling across the room, preparing them for later work on properties and changes of matter.

Essential Questions

• How can something like sugar or salt seem to “disappear” in water if matter cannot be created or destroyed?
• What evidence suggests that gases like air are made of tiny particles even though we cannot see them?
• How can a particle model help us explain everyday phenomena such as dissolving, mixing, and smells spreading?
• Why do scientists use models to represent things that are too small to see directly?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Describe matter as anything that has mass and takes up space, including solids, liquids, and gases.
2. Develop and use a particle model that represents matter as tiny pieces too small to see, arranged differently in solids, liquids, and gases.
3. Use observations from simple investigations (e.g., dissolving, mixing, compressing air, smells spreading) as evidence that matter is present even when it is not visible.
4. Draw and explain particle diagrams to show how particles are arranged and how they move in different situations.
5. Use the particle model to explain an everyday phenomenon in writing and/or orally (e.g., sugar in water, perfume spreading, air in a balloon).

Standards Alignment — 5th Grade (NGSS-Aligned)

• 5-PS1-1 — Develop a model to describe that matter is made of particles too small to be seen.
  • Example: Students draw and explain diagrams showing tiny particles of sugar spread throughout water after dissolving, or air particles being compressed in a syringe even though they cannot see the individual particles.

Success Criteria — Student Language

• I can explain that all matter, including air, is made of tiny particles that are too small to see.
• I can use particle diagrams to show how particles might be arranged in solids, liquids, and gases.
• I can describe how dissolving, mixing, or smells spreading can be explained using tiny particles moving and spreading out.
• I can use observations from our experiments as evidence that matter is still there even when I cannot see it.
• I can clearly explain an everyday event (like sugar dissolving or a scent traveling) with my particle model.