All lessons › Chemistry detectives › Lesson 1
Australian primary science · Years 5–6 · enrichment · Lesson 1 of 3
Periodic Table Detectives
Inquiry question: Which clues identify an element reliably?
Marked no materials needed
Research and classification
What students learn
Use names, symbols and atomic numbers to solve element mysteries and justify an identification.
Success criteria
- I can match a name, symbol and atomic number.
- I can use two clues and rule out an alternative.
- I can explain why an everyday use may not identify one element.
Preparation and materials
Before this lesson: Students know materials have properties; no symbol memorisation expected.
- Charged iPad per student or pair — 13 (one per pair)
- Projector / teacher screen — 1
Teacher setup
- Allow 55 minutes: Start 5, Investigate 25, Explain 15, Apply and hand in 10.
- Open the assigned QR and slides. No physical chemicals, samples or printed sheets are needed.
- Use supplied evidence if research sites are blocked. Books use the same questions and headings.
Safety and adaptations
- On-screen inquiry only. Do not collect, taste or mix substances, open batteries or try reactions seen online.
Review your school policies and curriculum requirements before teaching.
How to investigate
The lesson sequence should leave pupils with evidence to interpret, not only an activity to finish.
- Read Cases A–C and make tentative identifications.
- Open the element tool and check name, symbol and atomic number.
- Record two supporting clues per case and rule out an alternative.
- Find two answers to the electrical-equipment clue; invent a separating clue.
- Swap reasoning with a partner and improve one explanation.
Teacher modelling prompt
Model helium, He, atomic number 2: point to its labels without solving a case. Ask which number uniquely identifies helium.
Record and explain evidence
Recording question: Which element fits each case, and how do we know?
| Case | Name / symbol / number | Evidence and ruled-out alternative |
|---|---|---|
| ________________ | ________________ | ________________ |
Example recording headings; record actual observations, including inconclusive results.
Discussion prompt
Which claim do your cases support?
Provided example or reference data
Reference candidates · pure elements at about 20°C (RSC)
| Element / symbol | Atomic number | State | Useful clue |
|---|---|---|---|
| Carbon / C | 6 | Solid | Graphite is a form of carbon |
| Oxygen / O | 8 | Gas | Used in respiration |
| Neon / Ne | 10 | Gas | Reddish-orange discharge light |
| Aluminium / Al | 13 | Solid | Light metal used in foil |
| Copper / Cu | 29 | Solid | Wiring metal |
Check the data source in the teacher lesson. Illustrative or fictional data are not measurements collected by your class.
Check understanding
What should pupils know? What does atomic number tell us?
Explain with evidence: Why is 'solid metal' weaker than 'atomic number 13'?
Apply the idea: Write a fair two-clue mystery for another element; include answer, source and why it works.
Teacher answer guidance and saved classroom work are available through the main lesson experience where supported.