Simulation Description: Atomic structure – build an atom and ions with Protons, Neutrons and Electrons.
What it does
An interactive drag-and-drop atom builder covering AQA GCSE Physics and Chemistry. Students drag protons (red, +1), neutrons (blue, 0), and electrons (cyan, −1) from the bottom tray into a live animated atom. Protons and neutrons cluster in the nucleus; electrons orbit in shells (max 2 / 8 / 8). The header updates in real time showing the element symbol, name, atomic number, and mass number. A green glow confirms when the atom is electrically neutral. Shells enforce sequential filling — Shell 1 must be full before Shell 2 opens. Particles can be dragged back out to correct mistakes.
Suggested Class Activity — “Who Am I?” (15–20 min)
Year group: KS4 / GCSE (Y10–11)
Topic: Atomic structure
Setup: Students open the simulation on phones or tablets.
Task cards (teacher reads aloud or projects one at a time):
| Clue | Answer |
|---|---|
| I have 6 protons, 6 neutrons, 6 electrons | Carbon |
| I have 8 protons, 8 neutrons, 8 electrons | Oxygen |
| I have 11 protons, 12 neutrons, 11 electrons | Sodium |
| I have 17 protons, 18 neutrons, 17 electrons | Chlorine |
| I have 2 protons, 2 neutrons, 2 electrons | Helium |
Students build each atom, identify the element, and note: atomic number, mass number, and electron configuration (e.g. 2,8,1 for Sodium).
Exit question: “Why does sodium have 11 electrons but magnesium only needs 12 protons to be neutral?” — prompts thinking about what determines electron count in a neutral atom.