Density September 18 Warm - Up: density Today’s Agenda: 1. Denser than H2O Yes-No Activity 2. Density Notes & Powerpoint 3. Calculating density Reminders: Lab Report due tomorrow 18

2 28. density Draw it:Connect it: a comparison of how much matter there is in a certain amount of space. float or sink units: g/ml or g/cm 3

29. physical or chemical property 30. physical or chemical property 31. physical or chemical property 32. physical or chemical property

Denser than H 2 O Yes- No Activity

Billiard ball

Beach ball

Golf ball

Basketball

Marble

10 Bowling ball

11 Anchor

12 Log

Tennis ball

Volley ball

Ping pong ball

Inner tube

Rubber duck

Brick

Cork

20 Notes

What is density? Density is a comparison of how much matter there is in a certain amount of space.

Which one is more dense? Demonstration: Atoms in a square How about this: Which square is more dense? use the words mass & volume

Which one is more dense? Now which one is more dense?

What is density? Density = mass OR mass ÷ volume. volume Units for density: g OR _g_ cm 3 mL Why are these the units for density? What equipment do we use to measure density? ALWAYS REMEMBER NUMBERS HAVE LAST NAMES!

Let’s try a density problem together! Frank has a paper clip. It has a mass of 9g and a volume of 3cm 3. What is its density? Frank also has an eraser. It has a mass of 3g, and a volume of 1cm 3. What is its density?

Let’s try a density problem together: Will a can of Coke float or sink in water? Volume = 355 mL Mass = 394 g Will a can of Diet Coke float or sink in water? Volume = 355 mL Mass = 346 g

Liquid Layers If you pour together liquids that don’t mix and have different densities, they will form liquid layers. The liquid with the highest density will be on the bottom. The liquid with the lowest density will be on the top.

28 Sink or Float if an object/liquid has a smaller density than the liquid that it is place in it will FLOAT i f an object/liquid has a greater density than the liquid that it is place in it will SINK 27

29 Water has a density of 1 g/cm 3

Liquid Layers Observe this density column. Blue layer is water (density = 1 g/cm 3) Which layer(s) have a density greater than water? Which layer(s) have a density less than water? Imagine that the liquids have the following densities:  3 g/cm 3.85 g/cm 3.  8 g/cm 3 Which number would go with which layer?

Which liquid has the highest density? Which liquid has the lowest density? What is the density of water?

Liquid Layers – Try on your own! Imagine that the liquids on the right have the following densities:  15g/cm 3 10g/cm 3  3g/cm 3 9g/cm 3  7g/cm 3 12g/cm 3 Match the colors to the correct densities. 3g/cm 3 7g/cm 3 9g/cm 3 10g/cm 3 12g/cm 3 15g/cm 3

Why do lemons float and limes sink?

34 Using Density Pyramid

35 Strategy for Solving Word Problems 1. Read problem, what are you solving for? 2. What clues are in the problem? 3. Use the appropriate triangle. 4. Substitute the numbers 5. Solve, do the math -multiply numbers, if next to each other -divide numbers, if on top of each other 6. write answer with units

36 Clues Put in # & do the math Answer with units

37 Clues Put in # & do the math Answer with units

38 Clues Put in # & do the math Answer with units