Unit Plan 7 (Grade 5 Science): Evidence of Chemical Change
Grade 5 science unit where students identify gas, color, temperature, and new solid evidence when substances mix to determine if chemical reactions formed new substances.
Focus: Identify evidence of chemical reactions such as gas formation, color change, temperature change (heat absorbed/released), and formation of a new solid (precipitate) when substances are mixed, and use this evidence to decide whether new substances formed.
Grade Level: 5
Subject Area: Science (Physical Science • Matter & Chemical Change)
Total Unit Duration: 5 sessions (one week), 50–60 minutes per session
I. Introduction
In this unit, students deepen their understanding of chemical reactions by focusing on the evidence that a reaction has occurred. Building on prior work with mixing substances, they learn to recognize patterns such as gas production, unexpected color changes, temperature changes, and new solids forming in liquids. Through stations, demos, and guided investigations, students compare physical changes and chemical reactions and practice using evidence to support their conclusions about whether new substances have formed.
Essential Questions
- What observable signs can we use to tell that a chemical reaction has happened?
- How are gas formation, color change, temperature change, and new solids connected to the idea of new substances forming?
- How can we use careful observations and data to decide if a change is physical or chemical?
- Why is it important for scientists and engineers to correctly interpret evidence of chemical change when designing products and processes?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Describe common types of evidence that suggest a chemical reaction has occurred (gas, color change, temperature change, new solid).
- Conduct mixing investigations and record before and after observations with attention to these specific types of evidence.
- Distinguish between physical changes (like dissolving or melting) and chemical reactions based on observed evidence.
- Use an “Evidence of Chemical Change” checklist and data tables to decide whether new substances formed.
- Construct a short CER (Claim–Evidence–Reasoning) using observed reaction evidence to argue whether a chemical change occurred.
Standards Alignment — 5th Grade (NGSS-Aligned)
- 5-PS1-4 — Conduct an investigation to determine whether the mixing of two or more substances results in new substances.
- Example: Students mix pairs of substances and use specific evidence (gas, color change, temperature change, new solid) to decide if a chemical reaction has occurred, indicating new substances.
Success Criteria — Student Language
- I can name and describe four types of evidence for chemical reactions: gas, color change, temperature change, and new solids (precipitates).
- I can observe and record what happens before and after I mix substances, looking carefully for these signs.
- I can decide if a change is physical or chemical by using evidence, not just guesses.
- I can use an evidence checklist and a data table to support my ideas.
- I can write or explain a claim about whether a reaction happened and support it with observations and reasoning.