Electron configurations Where they go and why.

Orbitals What are they? S, P, D and F sublevels hold different numbers of orbitals What does each one hold? S sublevel: 2 electrons of opposite spin (1 orbital) P sublevel: 6 electrons of 3 clockwise 3 counterclockwise spin (3 orbitals) D sublevel: 10 electrons of 5 clockwise and 5 counterclockwise spin (5 orbitals) F sublevel: 14 electrons of 7 clockwise and 7 counterclockwise spin (7 orbitals)

S P D and F orbitals

Examples What is the outer orbital in Helium? What orbital is filling in Nitrogen? What orbital is the outside of Copper? What is the outside of Europium?

Drawing orbital filling Draw Arsenic. How do we use the shortcut? You can skip up to the Nobel Gas right before your element.

Pauli exclusion principle What does it say? An atomic orbital may only hold 2 electrons at one time. Each electron has to have a different spin (clockwise or counterclockwise).

Electron orbital filling What determines their order? The aufbau principle states that electrons occupy the orbitals of lowest energy first. How do we find this order?

Spin rules What determines the spin of the electron? Hund’s rule. This rule states that electrons fill the orbitals in a way that gives the atom the largest number of electrons with the same spin. What does this mean?

Stability What adds to the stability of the atom? Not all atoms follow the aufbau principle. Cr and Cu

Quantum numbers What are quantum numbers? Quantum numbers give us a different way to look at energy levels, sublevels, orbitals and spin. 3, 2, 2, ½ First is energy level Second is sublevel third is orbital Forth is electron spin

What are the rules for quantum numbers? First is a whole number 1-7 (n) Second is 0 to (n-1) (L) Third is +/- L (m) Fourth is +/- 1/2