EXAM #3 HAS BEEN MOVED TO MONDAY, NOVEMBER 9TH October 30, 2009 EXAM #3 HAS BEEN MOVED TO MONDAY, NOVEMBER 9TH

The First Three Quantum Numbers n, l, and ml are integers n = principal quantum # = 1, 2, 3, … n tells us the size/energy of the orbital l = angular momentum quantum # = 0, 1, 2, …, n-1 l tells us the shape of the orbital- s,p,d,f… ml = magnetic quantum number = –l to l ml describes the orientation of the orbital

Hydrogen

Nodes 1s (1,0) 2s (2,0) 1 2p (2,1) 3s (3,0) 2 3p (3,1) 3d (3,2) 4s Orbital (n,l) Planar Spherical Total 1s (1,0) 2s (2,0) 1 2p (2,1) 3s (3,0) 2 3p (3,1) 3d (3,2) 4s (4,0) 3 4p (4,1) 4d (4,2) 4f (4,3)

Nodes, Revisited # of planar nodes = l # of spherical nodes = n – l – 1 Total # nodes = n – 1 Example: 3d orbital

What orbital has these quantum numbers? n = 3, l = 2, ml = -1 4p 3d 3p 1d 2f

What are the quantum numbers for the 5dxy orbital? n = 5, l = 2, ml = 0 n = 5, l = -2, ml = 3 n = 4, l = 2, ml = 2 n = 5, l = 3, ml = 0 n = 5, l = 2, ml = -5

Which is not a valid set of quantum numbers? n = 4, l = 1, ml = -1 n = 1, l = 0, ml = 0 n = 6, l = 5, ml = -5 n = 2, l = 2, ml = 1 n = 3, l = 2, ml = 2

The representation 5d indicates which values for n and l? n = 5; l = 0 n = 5; l = 1 n = 5; l = 2 n = 5; l = 3

What is the total number of nodes for the 5d orbital? 1 2 3 4

How many spherical nodes does a 5d orbital have? 1 2 3 4

How many planar nodes does a 5d orbital have? 1 2 3 4

The Fourth Quantum Number n, l, and ml are integers n = principal quantum # = 1, 2, 3, … n tells us the size/energy of the orbital l = angular momentum quantum # = 0, 1, 2, …, n-1 l tells us the shape of the orbital- s,p,d,f… ml = magnetic quantum number = –l to l ml describes the orientation of the orbital ms is not an integer ms= spin quantum number = - ½ or ½

Electrons Spin Classical physics a spinning charge creates a magnetic field Electron spin* is quantized; the two states are called “spin up” and “spin down” *Electrons are described by quantum physics and don’t really “spin”

Electron Spin is the Source of Magnetism in Materials Diamagnetic Paramagnetic Ferromagnetic (“real magnets”)