1. Properties of Solids

2. Classifying Solids Solids can be classified according to
Arrangement of particles:
Amorphous solids – particles arrangements lack order (rubber & glass)
Crystalline solids – with organized particle arrangements and as a result a distinct shape
Bonds that hold them together (i.e. Ionic, covalent)

3. Properties of Solids
Properties of solids depend on the forces between particles
4 types of solids
Ionic (cation and anion)
Metallic (metals)
Molecular (nonmetals)
Covalent Network (metalloid/carbon)

4. Ionic Crystals High melting point Hard, brittle
High solubility in water
Electrolytes (in solution)

6. Metallic Crystals
Positive nuclei surrounded by loosely held valence electrons (metals have low ionization energies)
Creates a delocalized “sea” of valence electrons

7. 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.

8. Metallic Crystals Property Explanation Malleable, ductile
Nondirectional bonds, atoms can slide over each other while remaining bonded.
Conducts electricity
Free-floating valence electrons.
Conducts heat
Sea of electrons

9. Molecular Crystals
Soft
Low melting point
Nonelectrolytes

10. Covalent Network Crystals
Very hard and brittle
Very high melting points
Nonelectrolytes

11. 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.

12. Practice Unknown Solids Worksheet Solids Research Worksheet