quantum number keep in mind are probabilities of finding electrons in certain places doing certain...
TRANSCRIPT
Quantum Number
• Keep in mind are probabilities of finding electrons in certain places doing certain things(spin).
• n = what energy level (1, 2, 3, 4 . . .)• l = what sub-level (s, p, d, or f)• m = which orbital (s=1; p=3; d=5; f=?)• s = which spin (only two possibilities up or
down)
Pauli Exclusion Principle
• No two electrons ever have the same four quantum numbers in the same atom.
• Just as no two houses have the same address.
How are these organized?
n = 1
n= 2
n = 3
n = 4
Level 1 sublevels
Level 2 sublevels
Level 4 sublevels
Level 3 sublevels
ss
ss
ss
ss
p p
pp
pp
dd
dd ff
Remember: 1s is smaller than 2s, 2s is smaller than 3s, etc.
How about energy?
Which has the most?
How do atoms put their electrons in these sublevels?
• Lowest energy levels are filled first.
• Sublevels are filled “s”, then “p”, then “d”, then “f”.
• Well, sort of...
Orbitals
Pri
ncip
al q
uant
um n
umbe
r 3s 3p 3d
4s 4p 4d 4f
1s
2s 2p
5s 5p 5d 5f
6s 6p 6d 6f
7s 7p 7d 7f
s p d f
1
2
3
4
5
6
7
1s orbital holds two electrons
e-e-
e-e-
Then consider the next orbital: 2s (which also holds only two e-.)
e- e-
e-e-
Then consider the next orbital: 2p there are three of them
(which also hold two e-each)
e- e-
This is one of three.
Electron configuration for … Scandium
• Look up the number of electrons (same as the number of protons).
• Use the diagonal rule.
• Scandium is #21. That means Sc has _____ electrons.
2621
Electron configuration for … Scandium
1262622 3433221 dspspss
21s
Energy level (Principle Quantum #)
# of electrons(add these)
Sublevel
Electron configuration for … Scandium
1262622 3433221 dspspss
Add These
PracticeElectron configurations for:
• Neon
• Aluminum
• Vanadium
12622 33221 pspss1s22s22p6
1s22s22p63s23p1
1s22s22p63s23p64s23d3