Topic: Modern Model of the atom - ORBTIALS

Principal Energy Levels (PEL) Also known as “ shells ” Can have values of 1, 2, 3, 4….. (whole numbers) Electrons in PEL’s with greater numbers have greater energy. [Similar to rows of seats in a stadium)

Sublevels Each principle energy level is made up of 1 or more sublevels 1st PEL = s (1 sublevel) 2 nd PEL = s,p (2 sublevels) 3 rd PEL = s,p,d (3 sublevels) 4 th PEL = s,p,d,f (4 sublevels)

Orbitals s has 1 orbital p has 3 orbitals d has 5 orbitals f has 7 orbitals Each sublevel contains 1 or more orbitals Each orbital holds a max of 2 electrons 1st PEL = s (1 sublevel) = 1 orbital (____ electrons) 2 nd PEL = s,p (2 sublevels) = 4 orbtials (____ electrons) 3 rd PEL = s,p,d (3 sublevels) = 9 orbitals (___ electrons) 4 th PEL = s,p,d,f (4 sublevels) = 16 orbitals (____ e - )

Memorize SPD F e - 6e - 10e - 14e - s p d f *Each orbital holds a max of 2 electrons sublevels # of orbitals Max # of electrons

Orbitals s orbital: sphere p orbital: dumbell d orbital: 4 clovers,1 double ended pacifier f orbital: funky!! Flowers? You describe!

Bohr Model vs. Modern Model Electron = particleElectron = particle OrbitOrbit Holds 2n 2 electronsHolds 2n 2 electrons CircularCircular Each orbit has specific energyEach orbit has specific energy Exact locationExact location Electron = WaveElectron = Wave OrbitalOrbital Holds 2 electronsHolds 2 electrons Not necessarily circularNot necessarily circular Each orbital has specific energyEach orbital has specific energy Probable locationProbable location (wave mechanical model) (wave mechanical model)

Electron configurations Adding electrons to atoms so that the electrons are in the lowest energy levels – most stable or ground state configuration Start with 1s, then work upward in order of increasing energy. Use Aufbau rule.

Aufbau 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 4f 14 5s 2 5p 6 5d 10 5f 14 6s 2 6p 6 6d 10 7s 2 7p 6 7d 10

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 4f 14 5s 2 5p 6 5d 10 5f 14 6s 2 6p 6 6d 10 7s 2 7p 6 7d 10 He C Mg Zn 1s 2 1s 2 2s 2 2p 2 1s 2 2s 2 2p 6 3s 2 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10

He C Mg Zn 1s 2 1s 2 2s 2 2p 2 1s 2 2s 2 2p 6 3s 2 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 From these modern configurations, we can figure out Bohr Configurations All you have to do is add up the electrons in each shell (PEL) 1 = = 22 = – 4 1 = 22 = = 2 2 – 8 – 2 1 = 2 2 = = =2 2 – 8 – 18 – 2

Orbital Diagrams Shows the orbital the electron is located in Shows the spin – they have to be opposite!(spin up or spin down)

Hund’s Rule Maximum multiplicity – most e- with same spin. –So, Fill up before pairing up 1s 2 2s 2 2p 4

Which element? How many unpaired e-? How many PEL’s occupy? How many PEL’s are fully occupied? How many sublevels contain e-? How many sublevels full? How many orbitals contain e-? Boron