1. Questions lecture covers on test 1, 2, 3, 4, 13, 14, 15, 16, 30
Properties of Matter
Questions lecture covers on test
1, 2, 3, 4, 13, 14, 15, 16, 30

2. Intensive Properties-Do NOT change if you change the amount of substance
Example: softness, hardness, boiling point, melting point, hair color brown
Extensive Properties-Change as you change the amount of a substance: example: mass, volume, length, hair short

3. Physical Properties of Matter
Buoyancy
Density
Viscosity
Hardness
Brittleness
Elasticity
Malleability
Conductivity
Solubility
Tensile Strength

4. 1. Density
The “compactness.” It describes how tightly atoms are packed.
The relationship of
mass to volume
Density =
mass / volume

5. Buoyancy
The measure of the upward pressure a fluid exerts on an object
Buoyant force on an object = mass of the displaced fluid
will float if buoyant force > object mass
will sink if buoyant force < object mass
Shape affects buoyancy:
steel rod will sink in water
A sheet of steel (like a boat) displaces more water

6. Buoyancy and Flash Flooding
For each foot the water rises up the side of the car, the car displaces 1,500 lbs. of water.  In effect, the car weights 1,500 lbs. less for each foot the water rises.
The buoyancy of two feet of water will float most cars, allowing current to carry them away

7. Viscosity Measure of a material’s resistance to flow
Viscous fluids are thick and hard to pour
Determined by shape and size of molecules
Large, bumpy molecules create
more friction as they slide past
flow more slowly (MORE VISCOUS)
Small, smooth molecules flow
more quickly (LESS VISCOUS)

8. Hardness Measures a solid’s ability to resist scratching
Hard substances can scratch
softer substances
Ex. Diamonds are the hardest
natural substance on Earth
Does NOT mean rigid!

9. Brittleness
Measures a material’s tendency to shatter on impact (or to break without bending)
Ex. Glass shatters in car accidents
Now glass is made with a
shatter-proof coating that
holds the shards together
when glass breaks

10. 6. Elasticity
Measures a solid’s ability to be stretched and return to its original size
Gives objects the ability to bounce and withstand impact without breaking

11. 7. Malleability A solid’s ability to be pounded into thin sheets
Metals are very malleable (gold jewelry)

12. 8. Conductivity The ability of a material to conduct: Electric current
Heat
Sound

13. 9. Tensile Strength
A measure of how much pulling, or tension, a material can stand before it breaks
Important property of fibers
Ex: Spider silk fibers have more than 5 times the tensile strength of steel!

14. Chemical Properties
Reactivity
Flammability

15. Triple Beam Balance
Carry from base
Estimate the hundreths place
1.23

16. Graduated Cylinder More precise than a beaker
Accuracy-the degree of closeness to the actual value
Precision-repeatable; you get the same value each time

17. Accuracy vs. Precision High __________ low __________ Accuracy

18. Accuracy vs. Precision High ___________ Low ________ Precision

19. Why do you think the can of Coke sank and the can of Diet Coke floated?
What can you say about the density of the can of Coke compared to the can of Diet Coke?
What can you say about the density of the can of Diet Coke compared to water?
What is the density of water?
How can we calculate the density of the cans of Coke and Diet Coke?

20. In your journal collect Data
Mass of Coke=___________
Volume of Coke=___________
Density of Coke=_______________
Mass of Diet Coke=
Volume of Diet Coke=
Density of Diet Coke=