Chemistry from quantum numbers
Atoms
Pick any element. See its nucleus, its shells and every electron's place.
Two lobes of opposite sign, with a flat node through the nucleus.
Brightness is the chance of finding the electron there, |ψ|². Orange: ψ positive. Blue: ψ negative. Drag to turn it.
Element 6
Carbon C
- Protons (Z)
- 6
- Neutrons (≈, most common)
- 6
- Electrons
- 6
- Atomic weight
- 12.011 u
- Shells
- 2 · 4
- Block
- p-block
Configuration
[He] 2s² 2p²
Full: 1s² 2s² 2p²
Reading it: in 3d⁶, the 3 is the shell n (the energy level), the d is the shape ℓ (s = 0, p = 1, d = 2, f = 3) and the superscript 6 counts the electrons there.
Each shape holds 2(2ℓ + 1) electrons: s 2, p 6, d 10, f 14. Shell n holds 2n² in total. These are the same n, ℓ, m as the hydrogen derivation.
Subshells fill in order of n + ℓ (the Madelung rule), which is why 4s fills before 3d. A few elements, such as Cr, Cu and Au, break the rule because a half-full or full d shell is more stable.
Orbital boxes: one box per m, two electrons per box with opposite spin
Hund’s rule: electrons spread out one per box (same spin) before they pair. Pauli: no two electrons share all four quantum numbers. See the shapes of s, p, d orbitals →