1. Mass, Volume, & Density

2. Short Introduction Video
Why did the diet coke float and the regular coke sink?

3. Coke Can Experiment
When the cans of coke were placed in the beakers, the diet can floated but the regular can sunk.
Why?
Density: a property of matter that relates to the amount of mass to the volume taken up by the matter.
Density can be described with a mathematical equation:
D=M/V
Density is the amount of mass per unit volume

4. Density
Having seen that the Pepsi cans reacted differently in water, and knowing the reason is related to density, what can we determine about the differences between Pepsi and Diet Pepsi?
We know that the amount of fluid in both cans is the same
We can assume that the cans are the same material, same size, and therefore the same mass
Pepsi sank, Diet Pepsi floated, that must mean that the can of Pepsi is heavier
Because the cans are the same, that would mean that the fluid inside has a different mass ­ The Pepsi is heavier than the Diet Pepsi
Being that the volume of fluid is the same, that would mean that the density of Pepsi is higher than the density of Diet Pepsi (there is more mass in the same amount of the fluid)
Can you think of why Pepsi is more dense?

5. There are 3 states of matter: There are 3 states of matter:
Mass
Measurement of the amount of MATTER
(or stuff) in an object
Measured in GRAMS (g)
There are 3 states of matter:
Solid
Liquid
Gas
There are 3 states of matter:
Solid
Liquid
Gas

6. Volume Measurement of the amount of SPACE an object takes up
Measured in MILLILETERS (ml) or CUBIC CENTIMETERS cm3

7. Which do you think would have the greater volume? The greater mass? Why?
1 kg of rocks
1 kg of feathers

8. Density
Density is defined as MASS PER UNIT VOLUME. It is a measure of how TIGHTLY PACKED and how heavy the molecules are in an object. Density is the amount of MATTER within a certain VOLUME.
Density is the amount of matter within a certain volume.

9. Which one is more dense? Demonstration: People in a square
How about this: Which square is more dense?
BOX A
BOX B

10. Which one is more dense?
Now which one is more dense?
BOX A
BOX B

11. To find the density 1- Find the mass of the object
2- Find the volume of the object
3- Divide
Density = Mass g
Volume c³
ALWAYS REMEMBER UNITS!

12. Displacement Method
Awkward shaped object with a difficult volume to solve for?
Any object displaces a volume of water equal to it’s own volume when placed in water.

13. Find the mass of the object Find the volume of the object
To find density:
Find the mass of the object
Find the volume of the object
Divide : Density = Mass ÷ Volume
Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of space, calculate the density.

14. Find the mass of the object Find the volume of the object
To find density:
Find the mass of the object
Find the volume of the object
Divide : Density = Mass - Volume
Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of space, calculate the density
Set up your density problems like this:
Given: Mass = 35 grams Unknown: Density (g/ cm3) Volume = 7 cm3
Formula: D = M / V
Solution: D = 35g/7 cm3
D = 5 g/cm3

15. Let’s try some density problems together Work on these problems with your neighbor
1 Frank has a paper clip. It has a mass of 9g and a volume of 3cm3. What is its density?
2. Frank also has an eraser. It has a mass of 3g, and a volume of 1cm3. What is its density?
3. Jack has a rock. The rock has a mass of 6g and a volume of 3cm3. What is the density of the rock?
4. Jill has a gel pen. The gel pen has a mass of 8g and a volume of 2cm3. What is the density of the rock?

16. Find a Solid Object Density (Volume)
Step 1: Find the volume
If geometric in shape, you can use a ruler, a calculator and the volume formula to solve the volume
If it is a non-geometric shape you can use the displacement method

17. Find a Solid Object Density (mass)
Step 2: Find the mass
Use a triple beam balance
Tare to zero (make sure white lines line up)
Place object on tray
Slide movable masses (starting with front) until you have balanced white lines again
Use an electronic scale (ensure starting with 0.00g)

18. Find a Solid Object Density
Use the density equation (D=m/v)
Make sure your volume is in cubic centimeters (cm3) and your mass in is grams (g)