Choose an element
Atomic weights: CIAAW 2024, uncertainties omitted. Brackets show isotope mass numbers from the IUPAC 2022 table.
Where could the electron be?
Each dot is a possible position sampled from |ψ|². Dense regions mean higher probability per volume. The dots are not electrons or paths. In element mode, colors identify sublevels. Turn on wavefunction signs to color positive and negative phase; phase is not electric charge.
Sizes use the Bohr radius a₀ (≈ 0.0529 nm). Each orbital automatically fits the view; compare its radius below. Nucleus is exaggerated. A finite sample can miss small inner features.
Radial probability
P(r) = r²|R(r)|² · dashed lines mark radial nodes
Model, limitations & sources
Electron dot mode displays one position sample per electron per refresh: zero, one, or two dots in each orbital according to occupancy. Each dot samples its own orbital distribution. The full cloud allocates samples in proportion to orbital occupancy. Light atoms use the same samples per electron at a given budget; heavy atoms cap the count and increase the visual density weight per sample. Isolating sublevels or orbitals retains their existing points and the whole-atom viewing scale. The jumps are probability samples, not trajectories or a simulation of repeated measurements on individual electrons. In a selected p orbital, either phase-colored lobe can be sampled; signs do not force alternation. The radial chart continues to show the full probability distribution for the current selection.
Element mode uses occupancy-weighted, independent orbital densities: ρ = Σ occupancy × |ψ|²; wavefunctions from different orbitals are not added coherently. Radial sizes use hydrogen-like functions with approximate Slater screening, not a self-consistent or relativistic atomic calculation. The optional core lens maps r to log(1+r/a₀) and distorts distances to expose inner shells. The radial chart always uses physical radius. Open-shell orbital assignments are one Hund-rule teaching arrangement, not a unique orientation or exact many-electron ground-state wavefunction.
Configurations: NIST H–U, NIST / PDG through Hs, and Royal Society of Chemistry. Elements 109–118 are shown as predicted/reference configurations; superheavy configurations can differ among models. Ds and Rg follow the RSC reference convention.
Hydrogen-like Z = 1 wavefunctions: ψ = Rₙₗ(r)Yₗₘ(θ,φ), with associated Laguerre polynomials and normalized real spherical harmonics. Shells n = 1–7 include every allowed sublevel (s through i) and all 2ℓ+1 real orbitals. There are n−ℓ−1 radial nodes and ℓ angular nodes. Angular nodes appear as gaps in the cloud; only radial nodes have explicit wireframe guides. Colors have an arbitrary overall sign.
Positions are sampled from a numerical radial CDF and angular rejection sampling. This is a probability visualization, not a multi-electron simulation or an isosurface. Sampling is truncated at (4n² + 12n)a₀ for free orbitals, or that radius divided by the effective nuclear charge in element mode. Orbitals have no hard outer boundary.
NIST: Coulomb wavefunctions · OpenStax: the hydrogen atom