21 electrons sit in their real ground-state shells (K 2 · L 8 · M 9 · N 2 · O 0 · P 0 · Q 0 · 8 0 · 9 0 · 10 0). Each orbits and jitters as an agent. Heat or a tap lifts one into a higher shell (up to shell 10); it relaxes back and emits a photon.
Tap near an electron to excite it. The same ?seed= always gives the same run.
LITZ = 21, Sc, Scandium. Standard atomic weight 44.9559. Group 3, period 4, d-block.
LITGround-state configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 (NIST). Shells: K 2 · L 8 · M 9 · N 2 · O 0 · P 0 · Q 0 · 8 0 · 9 0 · 10 0.
LITFirst ionization energy 6.5615 eV (NIST).
LITIsotopes: 45Sc 100% (natural abundance).
LITEmission lines used for photons: 391.181 nm, 390.748 nm, the strongest neutral-atom (I) lines, air wavelengths, verified against the NIST Handbook of Basic Atomic Spectroscopic Data strong-lines table: https://physics.nist.gov/PhysRefData/Handbook/Tables/scandiumtable2.htm. Photons are not tied to a specific shell jump (ANALOGY).
WALLShells 8, 9 and 10 are MODEL, Dave’s 10-shell frame: no ground-state atom uses more than 7 shells, so they stay empty unless an electron is excited into them.
AMBERThe orbiting dots are a cartoon (ANALOGY), not orbitals; electron colour is by home shell (q.d), and the nucleus colour is by block (s, p, d, f). The self-check confirms the electron total equals Z, the shell counts sum to Z, every shell is within 2n², and shells 8 to 10 are empty in the ground state; any failure throws.