Want to get students thinking of themselves as science detectives? In this blog entry, you will get five hands-on cases to try along with a teacher guide. Each case includes an investigation and your choice of a Claim-Evidence-Response (CER) or Articulate-Connect-Extend (ACE) type response. Let’s take a look at these five packets.
Exploring the Science Detectives’ Five-Pack
The Science Detectives packet applies that routine to five short, hands-on cases. Each case includes a Page 1 investigation and your choice of a Page 2 response: CER or ACE.
| Case | Science focus | Students figure out |
|---|---|---|
| Mystery Mixture | Physical properties and separation | Which method separates each mixture |
| Density Deception | Mass, volume, and relative density | Which cube matches an unknown material |
| State Detectives | Melting, condensation, and evaporation | What changed and where energy moved |
| Magnet or Mimic? | Magnetic properties | Which objects respond to a magnet and why |
| Conductor Clues | Electrical conductivity | Which materials complete a low-voltage circuit |
1. Separate a Mystery Mixture
Students receive four teacher-prepared mixtures and a small set of tools: a magnet, sieve, water, filter, and magnifier. Their job is to choose a separation method based on an observable property.
The useful part comes after the separation. Students must explain why the method worked. “I used the magnet” is a procedure. “The magnet removed the iron because iron is magnetic and sand is not” shows the beginning of scientific reasoning.
2. Unmask an Unknown with Density
Four cubes look similar, but their masses tell a different story. Students measure mass and volume, calculate density, and compare their results with a short reference table.
This case is built to expose a familiar misconception: heavy objects sink and light objects float. A large piece of wood may weigh more than a tiny metal cube and still float. Density, not weight alone, explains the result.
I would use the completed example before handing students the blank case. It models how to move from measurements to a claim without turning the response into a fill-in-the-blank exercise.
3. Track a State Change
This investigation uses three water stations: melting ice, condensation on a cold cup, and evaporation from warm water. There is no fizzing tablet pretending to be a state change. Fizzing is evidence that students should examine as a possible chemical change, which belongs in a different case.
Students record what they see, measure temperature when appropriate, and identify whether thermal energy enters or leaves the system. The Extend prompt asks them to predict what would change if the room were warmer, the cup were colder, or the surface area increased.
4. Catch the Magnet Mimics
Metallic shine is a poor magnetism test, but students often treat it as proof. This case mixes steel, aluminum, copper, brass, wood, and plastic objects so appearance alone will not solve it.
After testing each object, students classify it and name a second property they could examine. That extra step keeps “metal” and “magnetic” from becoming accidental synonyms.
5. Follow the Conductor Clues
Students place one sample at a time into the gap of a safe, low-voltage circuit. If the lamp turns on, the sample conducted electricity. If it stays off, students check the connections before classifying the material.
A dark lamp may indicate an insulator, a loose clip, a dead battery, or a burned-out bulb.
Choose CER or ACE
Use CER when students need a formal scientific argument. They state a claim, cite specific evidence, and connect that evidence to a science idea.
Use ACE when you want to hear more of the student’s thinking. Students articulate what they learned, connect it to prior knowledge, and extend it with a prediction, application, or new test. Perhaps, use CER for lab reports and ACE for discussion, reflection, and transfer.
Print one case, gather the materials, and let students work the evidence before you supply the explanation.
Pair a hands-on case with a Science Critical Thinking Online Breakout for a digital follow-up.
👤 Human-directed (Miguel Guhlin) · 🤖 Gen AI-assisted (Claude, ChatGPT)
