Orbits and Orbitals

Basic Bohr to Quantum Orbitals

KLM to spdf

KLM and spdf???• KLM – Bohr style / old style lettering for

the “shells” or “orbits”. K is closest to the nucleus, L is next, M (N,O,P etc)

• Now we know that KLM is “really” the “Principle Quantum Number” 1,2,3 for the energy levels

• spdf – refers to the shape of the “orbital” –

A short deBroglie diversion

More rules

• No orbital can have more than 2 e- in it. (one spin up, one spin down)

• Orbitals are half filled (with spins in the same direction) before they are doubly filled.

• Orbitals are filled from lowest energy to highest energy.

Confusing?

• OK• “Quantum Numbers” are the way we can

describe locations where electrons can be found.

• The “Principle Quantum Number” – n – is the same as the old shells, and is the same as the number of the Period on the table.

n, l, m, s

• n = energy level (old shell / Bohr model)• l = angular momentum => shape

– s = 0 , p = 1, d = 2, f = 3– l ≤ n - 1

• m = magnetic quantum number => orientation– -l ≤ m ≤ +l

• s = spin ( +½, -½ or: up, down)

That didn’t Help!!!

• In the 1st level – Only an s orbital with 2electrons

• In the 2nd level, an s orbital with 2 electrons and a p orbital with 6 electrons

• OK, pictures are easier

S Orbital – SphericalOnly 1 S orbital per level, 2 e-

P orbital – Perpendicular 3 orbitals, 2e- each

D Orbitals – “double dumbbells” 5 orbitals, 2e- each, 10e- total

F orbital – “dead spiders”

7 orbitals – 2e- in each – 14 total*late breaking info – the above is correct, however since I went to school, a new shape –

the one in the middle, has been added

Now, How do you Fill Them

• You fill the orbitals from the lowest energy on up – Half filling them first, (with spins the same) then doubly filling them

Aufbau principle1s *we haven’t needed these yet

2s 2p3s 3p 3d4s 4p 4d 4f5s 5p 5d 5f 5g* 6s 6p 6d 6f*6g*6h*7s 7p

Some practice – Some Questions

• Look up the Atomic number, and then determine (not look up) the electron orbital configuration.

• H He• O K• Ca Cr• U Ag• Au Pt

Compare your configuration for Cr, Ag, Au and Pt with the “official” one.

Are they the same? If not, why are they different?

Noble Gas Configuration

1s2 He2s2 2p6 Ne3s2 3p6 Ar4s2 3d10 4p6 Kr5s2 4d10 5p6 Xe6s2 4f14 5d10 6p6 Rn7s2 5f14 6d10 7p6 Uuo

Olympicene

Pentacene

5 linked carbon rings with hydrogens

Fullerenes

Magic Numbers

2 – 8 – 8 – 18 -182 – 8 – 8 – 18 -18

2 – 6 – 10 – 14 2 – 6 – 10 – 14 (1,3,5,7)(1,3,5,7)

electronegativity

DisclaimerAloha

I put together these power points for use in my science classes.You may use them in your classes.

Some images are public domain, some are used under the fair-use provisions of the copyright law, some are mine. Copyright is retained by the owners!

Ted Brattstrom