Transcript Slide 1

Valence Numbers
Oxidation Numbers
Draw the orbital electron
configuration for the atoms of:
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Mg (magnesium)
K (potassium)
N (nitrogen)
Ne (neon)
Cu (copper)
And the answer is…
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Mg (magnesium)
↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓
1s2 2s2 2p6
3s2
K (potassium)
↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑__
1s2 2s2 2p6
3s2 3p6
4s1
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N (nitrogen)
↑↓ ↑↓ ↑ ↑ ↑
1s2 2s2 2p6
Ne (neon)
↑↓ ↑↓ ↑↓ ↑↓ ↑↓
1s2 2s2 2p6
Cu (copper)
↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓
1s2 2s2 2p6
3s2 3p6
4s2
↑↓ ↑↓ ↑↓ ↑↓ ↑
3d9
Why Do Atoms Bond?
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In order to achieve a complete
outer energy level.
2 electrons for H and He
 8 electrons for all other atoms
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If 8 is the ‘magic number’
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Mg (magnesium)
↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓
1s2 2s2 2p6 3s2
How many electrons would Mg need to gain?
How many electrons would Mg need to lose?
Which would be easier?
If electrons are (-) and protons are (+),
what charge would the atom have?
+2
If 8 is the ‘magic number’
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K (potassium)
↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑__
1s2 2s2 2p6
3s2 3p6
4s1
How many electrons would K need to gain?
How many electrons would K need to lose?
Which would be easier?
If electrons are (-) and protons are (+),
what charge would the atom have?
+1
If 8 is the ‘magic number’
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N (nitrogen)
↑↓ ↑↓ ↑ ↑ ↑
1s2 2s2 2p6
How many electrons would N need to gain?
How many electrons would N need to lose?
Which would be easier?
If electrons are (-) and protons are (+),
what charge would the atom have?
-3
If 8 is the ‘magic number’
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Ne (neon)
↑↓ ↑↓ ↑↓ ↑↓ ↑↓
1s2 2s2 2p6
How many electrons would Ne need to gain?
How many electrons would Ne need to lose?
Which would be easier?
If electrons are (-) and protons are (+),
what charge would the atom have?
0
Valence Numbers
Oxidation Numbers
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A SIGN number that indicate the
likely number of electrons that
would be lost or gained by an atom
in order to complete its outer
energy level.
Bonding potential
Location,Location, Location
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The location of an atom on the
Periodic Table of Elements can be
used to determine one of an
elements valences.
Except for Fe
 Some elements have more than
one valence number.
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 Additional
valence numbers must
be remembered.
+1
-4
+3 +4
+2
-3
+5 -2 -1
Nonmetals
+2 +2 +1 +2 +2 +1 +2 +2 +1 +2
Metals
Always +
+ or -
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