1. Properties of Solids

2. Physical properties
While solid has definite shape and volume; it does have various other properties that can be very different. Such as density, colour, melting points, etc
Pg. 119

3. Ionic solids Lots found in nature as rock and mineral deposits:
Sodium chloride (salt)
Potassium chloride (potash)
Also found at home:
Household cleaners (contains sodium hydroixde)
Other examples:
Rust (iron (III) hydroxide)
Tarnish (silver sulfide)

4. Cont’d
Some reactive metals don’t occur in elemental form in nature, they are found as ionic compounds
Ionic compounds are also used to extract metals from naturally occurring compounds
For example: iron is the most common metal used but is also very reactive

5. Formation
Formation reaction of a metal and nonmetal similar to sodium chloride
Formation reaction of two compounds
Ionic compound stability is similar to that of noble gases so it can be suggested that there is a total electron transfer occurring.

6. A model
At SATP, all ionic compounds are solid so they must be held together (bonded) in that rigid structure.
Models show that the ions are arranged in a regular pattern, depending on the size, shapes and charges
This is called a crystal lattice

8. Ionic Compounds Ionic compounds are brittle – the ions don’t rearrange
Binary ionic compounds also have medium to high boiling points
Polyatomic ions have more complex crystal lattices but the ions have covalent bonds so can be treated like an monatomic ion

9. Metallic Crystals
Shiny, silvery, flexible solids with good electrical and thermal conductivity
Hardness varies greatly as well as the melting temperature
X-Ray diffraction shows that all metals have a continuous and compact crystalline structure

10. Metal Properties Metallic bonding – continuous electron clouds
Low electronegativity – loosely holding electrons
Empty valence orbitals explains electron mobility
Strong Electrostatic attraction for bonding
this gives the many different properties to metallic compounds
Pg. 124

11. Molecular crystal Elements or compounds
Small molecules for solid crystal, low melting point, not very hard, nonconductors
Properties can be explained by the IMF and structure

12. Covalent Network Crystals
Crystal substances
Diamond and quartz – very hard
Very hard, high melting point, brittle, insoluble, nonconductors
Examples – silicon carbide SiC(s) used in sandpaper,

13. Carbon
Carbon is extremely versatile with bonding in various ways

14. Semiconductors
Crystalline silicon or germanium ‘doped’ with a Group 13 or 15 element
Little bit of energy to put an electron into a higher orbital and conduct electricity
Used in transistors, solar cells

15. Summary

17. Unit Test Review Summary
Lewis Formulas
Bonding Theory (types)
Electronegativity
Molecular Formulas (Lewis, structural, sterochemical)
Bonding capacity
VSEPR
Bond and molecular Polarity
Intermolecular Forces
Isoelectronic Compounds
Boiling points
Properties of Liquids and Solids

18. Suggested review questions
Pg. 137 #3, 6, 7, 10, 12, 14
Pg. 138 #21, 25, 28
Pg. 139 #35, 40, 41, 43
Pg. 140 #48, 53, 57
Pg. 141 #60