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1. Get the box of Stuff
Wood, steel, aluminum, melamine

2. Properties of Materials
Goal: Students will be able to
describe various physical
properties that materials have

3. Discussion
 differentiate between chemical and
physical properties
 At your tables list examples of chemical
and physical properties.
 I will call on each table and make a list of
all the ones we can think of.

4. Chemical Properties
 how a material interacts with another
material
 “social” behavior
 response to other matter (or lack of
response)
 reactions

5. Chemical Properties
 Examples:
 burning
 reaction with acid
 reaction with water
 corrosion/rusting/oxidation
 others????

6. Physical Properties
 characteristics it possesses by itself
(in and of itself)
 “personal” traits
 response to energy

7. Physical Properties
 color
 size
 texture
 melting point
 boiling point
 solubility
 luster
 density
 magnetism
 odor
 viscosity
 crystalline structure

8. Physical Properties
 Electrical properties
 conductor or insulator
 Optical properties – response to light
 index of refraction – bending of light
 transparent – light passes through
 translucent – some light passes through but no
distinct image
 opaque – no light passes through

10. Physical Properties
 Thermal properties – response to heat
 conductivity
 specific heat – how much energy it takes to
change temperature
 thermal expansion – example: iron wire
demo

11. Mechanical Properties
 subgroup of physical
 response to force or stress
 force – a push or pull
 stress – force causing a deformation or
distortion (force per unit area)

12. Mechanical Properties
Examples
 workability
 malleability – can be flattened
 ductility – can be drawn into wire
(stretched), bent, or extruded

13. Mechanical Properties
Examples
 brittleness
 breaks instead of deforming when stress is
applied
 hardness
 resistance to denting or scratching

14. Mechanical Properties
Examples
 elasticity
 ability to return to original shape after
being deformed by stress
 rubber ball or piece of elastic
 plasticity
 retains new shape after being deformed by
stress
 wet clay ball or piece of saran wrap

15. Some of the properties
 At your tables you will find some signs
with different physical properties.
 Go around between tables and answer the
questions on a separate piece of paper.

16. Index of Refraction
Question. What two materials here have a similar index of refraction?
(the three materials are glass, HDPE, and mineral oil)
Electrical conductivity
What materials here are non-conductive electrically?
(the materials are brass, copper coated steel, wax, glass and carbon fiber)
Hardness
Which material here is the hardest?
(Pine and Melamine)

18. Mechanical Properties
Examples
 toughness
 ability to absorb energy
 resistance to fracture
 strength
 resistance to distortion by stress or force
 several types: tensile, compressive,
torsional, bending, shear

19. Types of Stresses/Forces
 Tension
 pulling
 examples: tug-of-war, slingshot
 Compression
 pushing together or squeezing
 examples: bed springs, can crusher, bench vise

21. stress
strain
Ceramic or
glass
metal
polymer
straight line = elastic region
curved line = plastic region

22. City of Materials
 http://www.cityofmaterials.com

27. General Classes of Materials

28. Polymers

29. Ceramics

30. Composites

31. Metals and Alloys

32. Metals and Alloys

33. Wood and Wood Products

34. Free write
 On a piece of paper please describe
various physical and chemical properties
that material's have. If you can include
how you could test those physical
properties.