Each turn of the spiral is one period, winding outward from hydrogen. Elements in the same group sit on the same ray. Pick an element to zoom in and watch its electron orbitals pulse.
Lanthanides (La–Yb) and actinides (Ac–No) branch off between groups 2 and 3 into the two outer arcs. In Cosmic origin coloring, each tile is split in proportion to where the Solar System’s supply of that element was made. Lu and Lr sit in group 3, as in the IUPAC 2021 layout. Element data from the mendeleev database (NIST, NUBASE and CRC sources); values for elements past fermium are mostly predictions.