1. Properties of Matter
2.2 Physical Properties

2. What is a physical property?
A quality that of the material that can be seen or measured without changing the composition of the material (without changing what its made of)
Physical Properties:
Viscosity Melting point
Conductivity - Boiling point
Malleability - Density
Hardness

3. Examples of Physical Properties
Viscosity : the tendency of a liquid to keep from flowing, a liquid’s resistance to flowing.
The greater the viscosity, the slower the liquid moves
Examples: honey and corn syrup

4. Discuss Viscosity Turn to your neighbor…in 30 seconds
Choose two liquids to compare
Explain which of the two has a higher viscosity (which one resists flowing the most)
Listen as your neighbor does the same thing (compares two new liquids)

5. Conductivity A materials ability to allow heat to flow
Which spoon should you choose for stirring a pot of soup heating on the stove?
Wooden spoon or metal Spoon?
Why did you choose the spoon that you did?

6. Malleability The ability of a solid to be hammered without shattering
Most metals are very malleable
Other objects such as glass or fine china are easily broken

7. Hardness
One simple way to compare two materials is to see which one will scratch the other one
Which ever scratches the other is the harder of the two
A Diamond is the hardest known material and a 10 on Mohs scale of hardness

8. Examples
Provide an example for each of the following Something with high conductivity Something easily malleable Something that is softer than glass

9. Melting / Boiling Points
Melting point: the temperature at which a substance changes from a solid to a liquid For water normally occurs at 0o C Boiling point: the temperature at which a substance boils For water normally occurs at 100o C

10. Density
Recall that density is the ratio of the mass of a substance and its volume. This ratio can be used to test the purity of a substance Density = mass / volume
Sponge
Brick

11. Using Physical Properties
Physical properties are used to identify a material, to choose a material for a specific purpose, or to separate the substances of a mixture.

12. Using Properties to Identify Materials
Step One: Decide which properties to test Step Two: Test unknown sample Step Three: Compare results with data reported for known materials

13. Using Properties to Choose Materials
The properties of a material determine which materials are chosen for which uses. Example: You would not want shoe laces made of wood because they would not be flexible

14. Using Properties to Separate Mixtures
Some properties can be used to separate mixtures Filtration and Distillation are two common separation methods

15. Filtration
Is a process that separates materials based on the size of their particles Example: Using a strainer to remove tea leaves from a pot of tea

16. Distillation
Is a process that separates the substances in a solution based on their boiling points Example: on submarines sea water is boiled, the clean gas collected and cooled for drinking and the undrinkable compound left behind *This works because the clean water has a different boiling temperature than the compounds

17. Recognizing Physical Changes
Physical change occurs when some of the properties of a material change, but the substances in the material remain the same. Examples: crumpling a piece of paper and heating butter in a pan *Actions change the shape of the materials but not their composition

18. Quick Check
A material that is both malleable and conducts electricity well is most likely
Wood
Ice
Metal
Motor oil

19. Quick Check
Which of the following is NOT an example of a physical property?
Flammability
Malleability
Conductivity
Viscosity

20. Quick Check Which of the following is a ten on the hardness scale?
Granite
Quartz
Glass
Diamond

21. Quick Check Which of the following is an example of filtration?
Boiling sea water and collecting the clean gas
Water dripping through ground coffee beans to make coffee
Crumpling a piece of paper
Slicing a tomato in half