Structure & Properties of Solids
16
Structure & Properties of Solids Understanding the structural and bonding characteristics of substances in the solid phase – “materials 1
description
Structure & Properties of Solids. Understanding the structural and bonding characteristics of substances in the solid phase – “materials science”. Composite Materials. A material composed of two or more distinct materials that remain separate from each other in the solid phase. - PowerPoint PPT Presentation
Transcript of Structure & Properties of Solids
Structure & Properties of Solids
Understanding the structural and bonding characteristics of substances in the solid phase – “materials science”
1
2
3
Composite MaterialsA material composed of two or more distinct materials that remain separate from each other in the solid phase
4
Four types of solid structures we will explore:1. Ionic Crystals2. Metallic Crystals3. Molecular Crystals4. Covalent Network Crystals
6
Ionic Crystals
7
Form when metal reacts with non-metal
Composed of oppositely charged ions; electrostatically attracted to each other
Metallic Crystals
8
Metal atoms onlyBound by a “sea of electrons”;
creating overall region of negative charge explains metallic properties
9
10
Molecular Crystals
11
Composed of individual molecules held together by intermolecular forces
Properties vary depending on intermolecular forces present
Covalent Network Crystals
12
Atoms form covalent bonds in an inter-woven network
Properties:HardnessNon-conductorHigh melting
point
When heated beyond it’s MP, then cooled quickly, SiO2 changes from a) “sand” to b) “glass”
SiO2 glass can be strengthened by adding B2O3, used in lab and kitchen glassware (Pyrex)
14
SemiconductorsClick icon to add pictureType of covalent network solid (containing Si or Ge atoms)A substance that conducts a slight electric current at room temperatureA slight increase in temperature causes a significant increase in conductivity
15
www.youtube.com/watch?v=u3GdpbKTPQQ
Future of Materials Science 3D Printing
CNN: http://www.youtube.com/watch?v=e0rYO5YI7kA
Deeper explanation: http://www.youtube.com/watch?v=X5AZzOw7FwA
16
