1s2s 2p3s 3p 3d n = 1 n = 2 n = 3. nucleus 1s 2s 2p 3s 3p 3d 4s 4p4d 4f energy level sublevelstotal...
TRANSCRIPT
1s 2s 2p 3s 3p 3d
n = 1
n = 2n = 3
NUCLEUS
1s
2s 2p
3s
3p 3d
4s 4p 4d 4f
Energy Level
Sublevels Total Orbitals
1 s 1s
2 s,p 1s+3p = 4
3 s,p,d 1s+3p+5d = 9
4 s,p,d,f 1s+3p+5d+7f = 16
n n types n2
The Electron Configuration
• Explain the pattern of configuration using the Periodic Table.
• Explain the Aufbau, Pauli and Hund rules.
• Write the electron configuration or orbital box diagrams for a variety of atoms and ions.
Pauli Exclusion Principle
Electrons are constantly spinning which results in a magnetic field. Two electrons can occupy the same orbital only if they have opposite spins.
Each orientation for a sublevel contains a maximum of 2 e-.
Energy Level
Sublevels Total # e- capacity
1 s 1 2
2 s,p 1+3 = 4 8
3 s,p,d 1+3+5 = 9 18
4 s,p,d,f 1+3+5+7 = 16 32
n n types n2 2n2
1s 2s 2p 3s 3p 3d
n = 1
n = 2n = 3
Aufbau Principle
Unexcited electrons fill the lowest, most stable, energy orbital available – ground state.
Range of energies contains some overlap between higher principle levels.
Electron Configuration
Orbital Box Diagrams
1s 2s 2p 3s 3p 3d 4s
Hund ruleElectrons must enter empty orbitals of equal energy first before joining occupied orbitals.
Draw orbital box and electron config for carbon.
C: 1s2 2s2 2p2
1s 2s 2p 3s 3p 3d 4s
Draw orbital box and electron config for Mg.
Mg: 1s2 2s2 2p6 3s2
1s 2s 2p 3s 3p 3d 4s
Draw electron config for germanium.
Ge – atomic number 32
Ge: 4s2 3d10 4p2
Shorthand notation using noble gas “kernels.”
Ge: [Ar] 4s2 3d10 4p2
1s2 2s2 2p6 3s2 3p6
[Ar]
Energy level (n) of valence electrons is the same as the period of the atom.
Periodic Table shows orbital filling for the electron configuration of elements.
12345
Use the periodic table to help write the shorthand configurations for Mn and Ag.
Mn: [Ar] 4s2 3d5 Ag: [Kr] 5s2 4d9
Valence electrons are the electrons found in the outer-most or highest quantum level (n).
F = 9 electrons
1s2 2s2 2p5
The valence configuration is 2s2 2p5
Ge = 32 electrons
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2
The valence configuration is 4s2 4p2
Valence electrons also removed from highest quantum level (n) in positive ions.
F- = 9 electrons + 1
1s2 2s2 2p5
The ION configuration is 2s2 2p6
Fe+2 = 26 electrons - 2
1s2 2s2 2p6 3s2 3p6 4s2 3d6
The ION configuration is 1s2 2s2 2p6 3s2 3p6 3d6
Some exceptions to the rule:
Exceptions exist as the energy differences between higher energy sublevels become smaller.
Half-filled and completely filled subshells have extra stability – causes electron promotion.
Cr: [Ar] 4s2 3d4 Cu: [Ar] 4s2 3d9
Actual configurations:Cr: [Ar] 4s1 3d5 Cu: [Ar] 4s1 3d10
4s 3d 4s 3d
Electron promotion accounts for multiple ionization states (Fe+2, Fe+3…)
CAN YOU ? / HAVE YOU?
• Explain the pattern of configuration using the Periodic Table.
• Explain the Aufbau, Pauli and Hund rules.
• Write the electron configuration or orbital box diagrams for a variety of atoms and ions.