Warm-Up UV Radiation is always emitted when an electron falls back to which energy level? What color of light is emitted when an electron falls from n = 6 to n = 2?
Quantum Numbers
Quantum Numbers 4 different numbers to identify one specific electron in an atom Distance of orbital from the nucleus Shape of the orbital Orientation of the orbital Spin of the electron in the orbital
Principal Quantum Number (n) Indicates main energy level around the nucleus Possible values: 1, 2, 3, 4, 5, … (integers) n = 1 is closest to the nucleus and has the lowest energy
Orbital Quantum Number (l) Indicates shape of orbital Each energy level has different sublevels which are differentiated by their shapes Number of sublevels = n Possible values: 0 to (n-1) Possible orbital types: s, p, d, f (lowest to highest energy)
Orbital Quantum Number (l) Possible orbital types: s, p, d, f (lowest to highest energy) s 0 p 1 d 2 f 3
Orbital Types Energy Level n l Orbital Type
Orbital Types Energy Level n l Orbital Type 1 1s 2 2s 2p 3 3s 3p 3d 4 1s 2 2s 2p 3 3s 3p 3d 4 4s 4p 4d 4f
Orbital A region occupied by a maximum of 2 electrons As the number of energy levels increases, there are more orbitals # of orbitals in a main energy level = n2 Degenerate Orbitals – orbitals that have identical energies
Magnetic Quantum Number (ml) Describes orientation of the orbital about the nucleus (position) Possible values: -l to +l Orbital Type L Orbital Shape # of Orientations Notations S Sphere 1 P Peanut 3 Px, Py, Pz D 2 Daisy 5 Dxy, Dxz, Dx2, Dy2, Dz2 f Lots of lobes 7 complicated
s Orbitals
p Orbitals
d Orbitals
f Orbitals
Spin Quantum Number (ms) Indicates state of electron (direction of spin) Counterclockwise (Up) or Clockwise (Down) Only two possible values: +½ and -½
Pauli Exclusion Principle No two electrons can have the same set of 4 quantum numbers ever!!! If two electrons are in the same orbital, they must have opposite spins!
Practice – write the ?s and answers on a separate piece of paper 1) 2) 3) 4)
Practice – write the ?s and answers on a separate piece of paper 1) 2) 3) 4)