Free interactive chemistry · SIM-ATOM-001
Bohr atom builder
Build any atom or ion from protons, neutrons and electrons, and see what it is.
Open the interactive simulation →How to use this simulation
- Use the + and − buttons for protons, neutrons and electrons (or type the numbers).
- Watch the name, mass number and charge update at the top of the 3D view.
- Read the shell distribution and electron configuration in the side panel.
What to notice
- The number of protons alone decides the element.
- Changing neutrons makes isotopes; changing electrons makes ions.
- The Bohr shells are a teaching model — electrons do not follow circular orbits.
Try this
Build a chloride ion, Cl⁻. How many electrons does it have?
Try it for free →