Atomic Structure Lab

Read the model at a glance

Proton
positive
Neutron
neutral
Electron
negative
Change one control at a time. The atom, measurements, charge, shell arrangement, and graph update together.

Choose an investigation

Change the atom in real time

Measurements

Element
Atomic number
Mass number
Net charge

Selected structure

Tap a proton, neutron, electron, shell, nucleus, or photon to inspect it.

Electron-energy diagram

View and timing

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Teacher demonstration tools

Element identity depends only on proton number. Isotopes change neutron number; ions change electron number. Electron transitions exchange photons whose energies match the difference between allowed states.

Voice and language

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How the visual lecture works

① Listen
② Read
③ Watch
Every spoken sentence appears over the canvas. The orange arrow, glow, zoom, particle movement, or model change shows exactly what the sentence explains.

Current spoken explanation

Choose a chapter or start the complete lecture. Every spoken sentence will also appear on the canvas and activate a matching visual.

Detailed chapter explanation

10 sequential chapters

Detailed atomic structure guide

Nucleus
Protons and neutrons are nucleons. They occupy a region roughly one hundred thousand times smaller than the atom, yet hold nearly all its mass.
Atomic number and mass number
Atomic number is the proton count. Mass number is protons plus neutrons. Changing atomic number changes the element; changing only mass number creates an isotope.
Electrons
Electrons have negative charge and occupy quantum states. Shell drawings communicate energy levels but are not literal circular tracks.
Orbitals and probability
A cloud shows the probability of detecting an electron in a region. Denser areas mean greater probability, not more electron material.
Light and spectra
An atom absorbs or emits a photon only when the photon energy matches an allowed energy difference. This creates element-specific spectral lines.

Suggested experiments

  • Keep six protons and vary neutrons to build carbon isotopes.
  • Keep eleven protons and remove one electron to form sodium positive one.
  • Compare shell and cloud views; state what each model explains well.
  • Run the hydrogen transition and observe the outgoing photon.

Learning outcomes

  • Identify subatomic particles and their charges.
  • Calculate atomic number, mass number, and net charge.
  • Distinguish atoms, ions, and isotopes.
  • Explain discrete energy levels and spectral lines.
  • Interpret the electron cloud as probability.

Atomic structure assessment — 7 questions