Electron Distribution

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Electron Distribution

• Goal Determine electron structures in atoms
• Orbital level
• Sublevel

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How are these organized?
Level 1 sublevels
N 1
s
Level 2 sublevels
p
N 2
s
Level 3 sublevels
N 3
s
p
d
N 4
Level 4 sublevels
s
p
d
f
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Remember 1s is smaller than 2s, 2s is smaller
than 3s, etc.

• How about energy?
• Which has the most?

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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...

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Diagonal Rule
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1s orbital holds two electrons
e-
e-
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Then consider the next orbital 2s (which also
holds only two e-.)
e-
e-
e-
e-
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e-
e-
e-
e-
Then consider the next orbital 2p there are
three of them (which also hold two e-each)
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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.

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21
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Electron configuration for Scandium
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Electron configuration for Scandium
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PracticeElectron configurations for

• Neon
• Aluminum
• Vanadium