Reading the picture
Electrons do not orbit like planets. Each shell is drawn as a cloud of places an electron might be, with its electrons riding inside. Tap the atom to see the shape its newest electron lives in: s spheres, p dumbbells, d clovers, f flowers. Warm and cool lobes are the wave's two signs; dashed lines are nodal planes, where the electron is never found.
Sizes are covalent radii (Cordero 2008), true to scale within each row; the camera re-zooms for each new row. The nucleus is drawn far too big: a hydrogen atom is about 62,941 times wider than its nucleus, so a 1 cm nucleus would sit in an atom about 629 m across.
Of the 118 elements, 94 occur in nature. Shell counts, blocks, groups, unit conversions (1 eV = 96.4853 kJ/mol) and scale ratios are computed in code and checked by tests. Configurations for elements 109 to 118 are predictions.