1

Types of Types of SolidsSolids

Chap. 13: Day 4b

2Metallic and Ionic Metallic and Ionic SolidsSolids

Sections 13.6-8Sections 13.6-8

Metallic and Ionic Metallic and Ionic SolidsSolids

Sections 13.6-8Sections 13.6-8

3

Properties of SolidsProperties of Solids

1. 1. Molecules, atoms or ions locked into a CRYSTAL LATTICE

2. Particles are CLOSE together

3. STRONG IM forces

4. Highly ordered, rigid, incompressible

ZnS, zinc sulfideZnS, zinc sulfide

4

5

Types of SolidsTypes of SolidsTable 13.6Table 13.6

TYPETYPE FORCE Properties . FORCE Properties .

Ionic Ionic Ionic Ionic Hard, brittle, High MP Hard, brittle, High MP

poor conductorpoor conductor

Metallic Electrostatic Metallic Electrostatic Malleable, Range of MP Malleable, Range of MP

good conductorgood conductor

MolecularMolecular Dipole Soft, Low of MP Dipole Soft, Low of MP

Ind. Dipole poor conductorInd. Dipole poor conductor

NetworkNetwork Extended Extended Range of MP & hardnessRange of MP & hardness

covalent covalent poor conductorpoor conductor

6

Network SolidsNetwork Solids

DiamondDiamond

GraphiteGraphite

7

Network SolidsNetwork Solids

A comparison of diamond (pure carbon) A comparison of diamond (pure carbon) with silicon.with silicon.

8Atom Packing in Unit Atom Packing in Unit CellsCells

Assume atoms are hard spheres and that crystals are built by PACKING of these spheres as efficiently as possible.

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10

11

Crystal LatticesCrystal Lattices• Regular 3-D arrangements of equivalent

LATTICE POINTS in space.• Lattice points define UNIT CELLS

– smallest repeating internal unit that has the symmetry characteristic of the solid.

12Cubic Unit Cells of Cubic Unit Cells of MetalsMetalsFigure 13.24Figure 13.24

Simple cubic (SC)Simple cubic (SC) Body-Body-

centered centered cubic (BCC)cubic (BCC)

Face-Face-centered centered cubic (FCC)cubic (FCC)

PROPERTIES

OF LIQUIDS

Chap. 13: Day 4a

Intermolecular Forces

The forces BETWEEN molecules. Holds the molecules together. At a set temperature:

What phase has the strongest force? Solids

What phase has the weakest forces? Gases (vapor)

Viscosity•the resistance of a fluid to flow

Thick fluids have high viscosity

Vapor Pressure

The pressure exerted by a vapor in equilibrium with its liquid state.

The pressure at which liquid changes to vapor

Liquids with high vapor pressures turn into vapors very easily. (Volatile)

Ex. Gasoline, perfume

Once equilibrium is reached, the vapor particles will begin to condense back to a liquid

Boiling Point

The temperature at which the vapor pressure of the liquid equals the atmospheric pressure

The entire liquid is changing state, not just the surface.

Water boils at 1000C

at standard P

Vapor Pressure vs Temperature

Liquid Properties Surface Tension- Ability of liquid molecules to

hold on to each other. Apparent “skin” affect Ex. Over filling a liquid in a glass with out the

liquid spilling

Hg

Liquid Properties

Capillary Rise- the tendency of a liquid to rise in a small diameter tube due to the surface tension of the liquid.

INTERMOLECULAR FORCES

STRONG Forces lead to….

Nonvolatile Substances

High boiling points Low evaporation

rates Low vapor P at

room temperature

WEAK Forces lead to..

Volatile substances

Low boiling points High evaporation

rates High vapor P at

room temperature