Metallic bonding

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Metallic bonding
is an electrostatic attraction between sea of
electrons and positive ions. Metallic radius as
half the internuclear distance between two atoms
in a metallic crystal. Factors affecting the
strength of metallic bonding Because 1. b.p.
Al gt Mg gt Na Therefore.. 2. b.p. Li gt Na gt
K Therefore
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Metallic bonding

• Factors affecting the strength of metallic
  bonding
• number of valence electrons (outermost electrons
  / bonding electrons) and charge on cations.
• Therefore.. b.p. Al gt Mg gt Na
• 2. metallic radius.
• Therefore ..b.p. Li gt Na gt K
• i.e. larger no. of valence electrons, smaller
  metallic radius will result in stronger metallic
  bonds.

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Metallic bonding
10.1 Nature of metallic bonding 10.2 Metallic
radius 10.3 Factors affecting the strength of
metallic bonding
Question Explain why there is such a large
difference in melting point and boiling point of
metals. Given m.p. Na 97.90 oC, K 63
oC b.p. Na 883.1 oC, K 774 oC
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Metallic bonding
10.4 Metallic crystals
Close-packed structure
Open structure
68 of space occupied by atoms/ co-ordination
no. 8
74 of space occupied by atoms / co-ordination
no. 12
Cubic close-packed structureabcabc
Hexagonal close-packed structureabab
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10.4 Metallic crystals
Hexagonal close-packed structureabab
74 of space occupied by atoms
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10.4 Metallic crystals
abab and abcabc
co-ordination no. 12
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10.4 Metallic crystals
74 of space occupied by atoms / co-ordination
no. 12
Cubic close-packed structureabcabc
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10.4 Metallic crystals
Open structure
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10.4 Metallic crystals