Transcript Properties of Solids

Properties of Solids
Classifying Solids
Solids can be classified according to
1. Arrangement of particles:
Amorphous solids – particles arrangements lack
order (rubber & glass)
Crystalline solids – with organized particle
arrangements and as a result a distinct shape
2. Bonds that hold them together (i.e. Ionic, covalent)
Properties of Solids
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Properties of solids depend on the
forces between particles
4 types of solids
1.
2.
3.
4.
Ionic (cation and anion)
Metallic (metals)
Molecular (nonmetals)
Covalent Network (metalloid/carbon)
Ionic Crystals
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High melting point
Hard, brittle
High solubility in water
Electrolytes (in solution)
Metallic Crystals
• Positive nuclei surrounded by
loosely held valence electrons
(metals have low ionization
energies)
• Creates a delocalized “sea” of
valence electrons
Metallic Crystals
Property
Explanation
Crystalline
Electrons act as electrostatic glue.
Hard & dense Strong attraction between electron sea and
positive nuclei.
Lustrous
Valence electrons absorb and re-emit many
wavelengths of light.
Metallic Crystals
Property
Explanation
Malleable, Nondirectional
ductile
bonds, atoms can
slide over each
other while
remaining bonded.
Conducts Free-floating
electricity valence electrons.
Conducts
heat
Sea of electrons
Molecular Crystals
• Soft
• Low melting point
• Nonelectrolytes
Covalent Network Crystals
• Very hard and brittle
• Very high melting points
• Nonelectrolytes
Covalent Network Crystals
– Carbon forms several allotropes (different forms) of
network solids including the arrangement in graphite vs.
diamond.
– These arrangements give each type of network
different chemical and physical properties.
Practice
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Unknown Solids Worksheet
Solids Research Worksheet
P. 273 #1-5, 7
P. 276 #1-8