Structure of Solids Chapter 11 Part III. Classification of Solids Crystalline Solids with highly regular arrangement of components Amorphous Solids with.

Structure of Solids

Chapter 11

Part III

Classification of Solids

• Crystalline• Solids with highly

regular arrangement of components

• Amorphous• Solids with

considerable disorder in their structure.

X-ray Diffraction

• X-ray Diffraction is commonly used to determine the structure of a solid.

• X-ray diffraction is explained on page 420.

Crystalline Solids• A Lattice represents

the regular positioning of the components of a crystal.

• A Lattice is the three dimensional system of points designating the positions of the components.

• The smallest repeating unit of the lattice is called the Unit Cell.

Unit Cell-Simple Cubic, Body centered cubic & Face centered

cubic.

Types of Crystalline Solid

• Ionic Solids: metal and non metal

• Molecular solids: non metal and non metal

• Atomic solids: single element

Ionic Solids: metal and non metal

• Ionic substances have ions at the point of the lattice that describe the structure of the compound.

• Examples: NaCl, FeSO4, Al2S3

Molecular solid: non metal and non metal

• Molecular solids have discrete covalently bonded molecules at the end of each of its lattice points.

• See ice →

Atomic solids: single element

• Atomic solids all have atoms at the points of the lattice that describes the structure of the solid.

• This example is diamond a network covalent solid.

• Other examples include, boron, silicon and all metals.

Types of solids

Atomic solids: Three types

• Metallic Solids

• Network Solids

• Group VIIIA solids

Metallic Solids

• These have a type of delocalized non-directional covalent bonding.

• Examples are Cs and Au

Network Solids

• The atoms bond to each other with strong directional covalent bonds that lead to macromolecules or networks of atoms.

Group VIIIA solids

• Noble gases are attracted to one another at low temperatures with weak London dispersion forces.

• The examples are Kr and Xe. Both are cubic close packed.

Summary

Classification of solids

Atomic SolidsMolecular Solids

Ionic Solids

Metallic Network Group VIIIA

Components that ocupy the lattice points Metal Ions

Nonmetal atoms

Group VIIIA atoms

Discrete molecules Ions

BondingDelocalized covalent

Directional Covalent (marcomolecules)

London Dispersion Forces

Dipole-dipole and/or London dispersion forces Ionic

Structure and Bonding in Metals