1. Sink Float Suspend Challenge
Challenge: Make the film canister float, make the film canister sink, Then make the canister stay suspended in the middle Safety: Keep water at the sinks Clean up any spills Act in a responsible manner

2. Sink Float Suspend Challenge
Did the mass change?
Did the volume change?
How does a sub work?
What other objects sink?
What other objects float?
What determines if something can sink or float?
Sub:

3. If volume> mass it will float
If mass>volume it will sink
If mass=volume it will be suspended

4. Ask a question: What is happening? Why?

5. Why do these float?

6. Floating and Sinking Orange Demo
What will an orange do in water?

7. Explain this???
Why does an orange with a peel float, but without its peel, it sinks?
How did its mass change?
How did its volume change?
What determines if something can sink or float? Its mass? Its volume? Both?

8. Density

9. What is density?
Density is a ratio of how much matter there is in a certain amount of space.
A measure of how many particles are packed into a certain area.

10. More dense = more particles in a space
Less dense = less particles in a space

11. How do I find density?
I need to find out how much stuff (mass) is in a certain amount of space (volume)

12. What instruments do I need?
To find the volume of the object
Ruler or graduated cylinder
Units are cm3 or mL
To find the mass of an object
Triple Beam Balance
Units are g

13. How do I calculate density?
Density = mass OR mass ÷ volume.
volume
Units for density: g/cm3 or g/mL
ALWAYS REMEMBER UNITS!

14. Does the sample size affect the density of an object?
Do all these pieces of gold have the same density?

15. Does the sample size affect the density of an object?
In other words, if I break off a piece of this cube, will it have a different density than the whole piece?
NO!!!

16. Density is based on total mass divided by total volume.
When one changes, the other also changes, so the density (which is a ratio) stays the same!!!

17. Which one is more dense?
Which table group is most dense in the classroom?
How about this: Which square is more dense?

18. Density of Water Water has a density of 1g/mL
If an object has a density greater than 1g/mL, it will sink in water
If an object has a density of less than 1g/mL, it will float in water.

19. What do we know about the density of diet coke vs. coke vs. water?

20. Do liquids have different densities?
Yes! So what happens when you mix them?
They form layers with the most dense liquid falling to the bottom.
Alcohol = .80 g/ml
Vegetable Oil = .90 g/ml
Water = 1.0 g/ml
Salt Water = 1.2 g/ml

21. The density of the liquid affects how you float too!
Denser liquids help you float more easily.
That is why it is easier to float in the ocean, than in a freshwater lake.

22. Illustrating Density

23. Metals have different densities
Lead 11.3 g/cm3
Aluminum 2.7 g/cm3
These are all over 1.0 g/ml and most ships are made of metal. So how do boats float?

25. Explain why one bowling ball floats and one sinks

26. Density affects many of Earth’s processes

27. Density helps create ocean currents

28. Density helps move melted rocks under Earth’s crust
mantle
core
Hot material rises, cooler material sinks, creating a current, called a Convection Current

29. Solid Land has different densities
Continental Plates – lighter, thicker, (less dense) made of granite
Oceanic Plates – heavier, thinner, (more dense) made of basalt

30. Convergent Boundary Plates move toward each other
The more dense oceanic plate subducts under the less dense continental plate

31. Normal and Low bone densities
Low density bones break more easily.

32. Temperature can affect density
Remember. . . Warm air rises.
So this means warm air is less dense than cold air and it rises

34. Density causes your attic to be hot in the summer

35. Try it!
Follow the directions for the ice experiment and see if you can explain what is happening
Safety: Wear your goggles! Clean up spills. Follow all directions. No eating or drinking during lab.

36. Step 1
50 mL isopropyl alcohol
50 mL water
4 ice cubes

37. Step 1. Observations Make observations about: Ask Questions
State of matter
Color
Odor
Temperature
Clear/opaque
Other
Ask Questions

38. Step 2
50 mL isopropyl alcohol
50 mL water
4 ice cubes

39. Step 3- after 5 minutes 50 mL isopropyl alcohol 50 mL water
4 ice cubes

40. Explain what happened? Density of known substances
Water 1g/ml
Ice g/ml
alcohol g/ml
What do the ice cubes do in water? Why?
What do the ice cubes do in alcohol? Why?
What do the ice cubes do in alcohol after 5 mins? Explain why using data to support your conclusion.

41. Where would an ice cube go if I dropped it in this container?

42. Materials denser than water sink Materials less dense than water float

43. Identifying matter using Density
What material is this block made of?
How can I figure it out?
Find its mass (135g), find its volume (15mL), calculate its density.
135g/15mL = ?
Then compare your answer with the known substances to identify it.