Electron Configuration

This interactive simulator explores Electron Configuration in Chemistry. Fill orbitals visually with Aufbau principle animation. Use the controls to change the scenario; watch the visualization and any graphs or readouts to connect the model with lectures, labs, and homework.

Who it's for: Best once you already know the basic definitions and want to build intuition. Typical context: Chemistry.

Key terms

  • electron
  • configuration
  • electron config
  • chemistry

Aufbau prediction

1s22/2 eโป
2s22/2 eโป
2p66/6 eโป
3s22/2 eโป
3p44/6 eโป

Reference (periodic dataset)

1s22/2 eโป
2s22/2 eโป
2p66/6 eโป
3s22/2 eโป
3p44/6 eโป

Compact notation

1s2 2s2 2p6 3s2 3p4

1s2 2s2 2p6 3s2 3p4

Sulfur or sulphur (see spelling differences) is a chemical element with symbol S and atomic number 16. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8.

How it works

**Aufbau** filling (Klechkowski order) predicts how subshells fill with increasing **Z**. Many ground-state atoms follow it, but **exceptions** (Cr, Cu, Mo, Pd, โ€ฆ) lower the energy by promoting one **s** electron into **d** or **f**. The **reference** row uses curated configurations from the periodic dataset.

Key equations

Order: 1s โ†’ 2s โ†’ 2p โ†’ 3s โ†’ 3p โ†’ 4s โ†’ 3d โ†’ 4p โ†’ โ€ฆ