Lesson Plan

• Describe what the proton (atomic) number represents and how it relates to the nucleus.
• Explain how the proton number determines element identity and its position in the periodic table.
• Calculate the proton number from a given mass number and neutron count.
• Identify and correct common misconceptions about atomic number versus mass number.
• Use visual models to illustrate the concept of proton number in atoms.

• Projector or interactive whiteboard
• Printed element cards or digital set
• Coloured beads (red, blue, green) and string for atom models
• Worksheet with isotope calculations
• Periodic‑table handout
• Whiteboard markers

Begin with a quick question: “What tells us which element an atom is?” Connect this to students’ prior work on atoms and isotopes. State that by the end of the lesson they will be able to define and use the proton (atomic) number accurately.

1. Do‑now (5'): Students write the definition of atomic number from memory; teacher collects responses.
2. Mini‑lecture (10'): Explain proton number (Z), its notation, and its role in element identity using slides.
3. Interactive activity (12'): Students arrange element cards in order of increasing Z to build a simple periodic table.
4. Hands‑on modelling (10'): Using coloured beads, groups construct an atom model and count red beads to confirm Z.
5. Guided practice (8'): Worksheet problems where students calculate Z from A and N and address misconceptions.
6. Quick check (5'): Exit ticket – one sentence: “Why does the atomic number equal the number of electrons in a neutral atom?”

Recap that the proton number uniquely defines an element and determines its place in the Periodic Table. Ask a few students to share one misconception they corrected today. Assign a short homework: complete a table listing five elements with their Z and A values.