1. GRAPHING AND VARIABLES
X axis—holds the independent (manipulated) variable Y axis—holds the dependent (responding) variable ***DRY MIX***

2. ACTIVATOR: WORD SPLASH--MEASUREMENT
List as many terms or phrases that we’ve discussed in unit 2 that deal with measurement

3. DATA TABLES AND VARIABLES
X (INDEPENDENT)
Ex: Volume (mL)
Y (DEPENDENT)
Ex: Mass (grams)
2.0
7.9
3.0
16.2
4.0
25.0
5.0
32.3

4. SLOPE Is determined by the first and last data points
Last y – first y = y2 - y1
last x – first x x x1
Ex: – = = 8.1
5.0 –

5. DIRECT VS. INDIRECT PROPORTIONS
INDIRECT (aka INVERSE)
Shows a positive slope
Shows a negative slope
both factors increase or both factors decrease (do the same thing)
Factors do opposite things
Ex: speed = distance/time
density = mass/ volume
Ex: area = length x width
Graph:

6. FLIPPED ASSIGNMENT--DENSITY
Visit the following website:
nsity_sample_problems.htm
Review all 3 types of density problems posted on this page before class tomorrow.

7. ACTIVATOR: Explain why these substances are layered?

8. DENSITY DEMONSTRATIONS: (TEACHERTUBE.COM)
1. The density of liquids
2. Underwater volcano
3. The density of water is 1
4. Dr. Reich’s density lab
p?video_id=7593

9. FOR DENSITY LAB:
--follow your procedure !!!
---DO NOT MOVE CHAIRS AROUND
---MUST KEEP GOGGLES ON AT ALL TIMES at station 2!!!
---PART OF YOUR GRADE IS BASED ON CLEAN UP
---WHEN USING SOAP TO WASH CYLINDER, ONLY USE 1 DROP!
---stay with your group and stay quiet!!
--- calculate all densities after coming to sit down

10. On your data table, add: PART C: Mass of red block= Length = Width=
Height=
Volume =
Density =

11. DENSITY LAB CONCLUSIONS
ANSWER 1—5
For #2 you will need these accepted values.
% error = measured – accepted x 100
accepted
Water = 1.00 g/mL
Liquid A (isopropanol)= g/mL
Liquid B (glycerin) = 1.26 g/mL
Solid sinker (lead alloy) = g/cc
Red wood (alder) block = 0.4 g/cc

12. DENSITY DENSITY = MASS VOLUME **this is a direct proportion**
As mass increases, volume increases (or as mass decreases, volume decreases)
Units that measure density:
Solids: g/cm3 liquids: g/mL gases: g/L
**see density chart p. 38

13. Specific gravity
The density of a substance compared to water’s density (1.0 g/mL)
Float = density less than water
Sink = density greater than water

14. p. 40 (SHOW WORK AND INCLUDE CORRECT UNIT)
#1. What is the density of a block of marble occupying 310. Cm3 and a mass of 853 grams?
#2. Diamond has a density of 3.26 g/cm3 and a volume of cm3. Find the mass.
#3. What is the volume of a sample of mercury having a mass of 76.2 grams and a density of 13.6 g/mL?

15. ANSWERS
g/cm3
grams mL

16. 4) If a sample of lead is cut in
half, will its density change?
Explain why or why not.

17. No b/c mass AND volume both change
by the same factor

18. 5) Find the density in grams/mL of a
liquid having a mass of 2 kg and a volume of 2900 mL.
What might this liquid be?
(see p. 38)
Would it sink or float in water?

19. 2000 grams / mL = g/mL
It would float because it’s density is less than water’s

20. SUMMARIZER: DENSITY 3-2-1
Name 3 measurements the density formula involves.
Give 2 units that measure density.
Give 1 reason an object may float in water.

21. ACTIVATOR: (using your calculator)
Calculate the density of a gas with a mass of 253 grams and a volume of 3.5 L.
SHOW YOUR WORK

22. ACTIVATOR:
Using the Density chart below, name 2 substances that will float in water AND 2 substances that will sink in water.
Brass
Gold
Iron
Uranium
Ice at 0 C
Wood

23. Homework Density handout front 1—13 ****also read LAB carefully
back ODD
****also read LAB carefully
Finish IPAD activity

24. DENSITY HANDOUT ANSWERS-FRONT SIDE
g/mL
g/cc (could be Aluminum which has density of 2.7 g/cc)
grams mL
g/cc mL
g/mL
grams cc
g/mL
g/cc
grams
g/mL

25. BACK---ODD 1--20 1. 0.23 g/cc 3. 0.14 g/cc 5. 0.21 g/cc 7. 0.27 g/cc

26. EXTRA PRACTICE --DENSITY
3. 2
5..

27. SUMMARIZER—using the density formula
How is density calculated?
How is mass calculated?
How is volume calculated?

28. ACTIVATOR
Calculate the volume of a block of wood having a denisty of 0.78 g/cm3 and a mass of 300 grams.

29. WARM UP—DENSITY & GRAPHING
1. Calculate the density of a liquid having a mass of 35 grams and a volume of
111 mL
2. Calculate the mass of a solid having a density of 2.5 g/cc and a volume of 3 cc.
3. Calculate the volume of a block with a mass of 9.0 grams and a density of 45 g/cm3.
4. Find the density in grams/mL of a liquid having a mass of 3.4 kg and a volume of 1.0 L.
5. If a sample of gold is cut in half, would its density change. EXPLAIN WHY OR WHY NOT.
ANSWER THE FOLLOWING QUESTIONS USING THE DATA TABLE BELOW:
MASS (g) VOLUME (mL)
6. Calculate slope of the graph’s line.
7. Is this a direct or indirect relationship?
8. What is the responding variable?
9. What is the independent variable?

30. SUMMARIZER
Describe how the density is measured for an irregular shaped solid VS. a rectangular shaped solid.

31. p #5
p #1, 2
p #7-10
p # 13b,c 14a,b , 22a,b b, 33b

32. ACTIVATOR
Put the object’s in the lab in order of least to greatest density:
Water = 1.00 g/mL
Liquid A (isopropanol)= g/mL
Liquid B (glycerin) = 1.26 g/mL
Solid sinker (lead alloy) = g/cc
Red wood (alder) block = 0.4 g/cc
Which ones would sink in water? Which ones would float in water?

33. QUIZ-- DENSITY= mass/volume
REMEMBER SIG FIGS AND UNITS!!
SHOW WORK!!
Calculate the density of a solid having a mass of 45 grams, a length of 2 cm, a width of 3 cm, and a height of 1 cm.
An object’s density is 3.6 g/cc. It is put into a graduated cylinder initially having mL. The water level rises to 25.2 mL. What is the object’s mass?
Find the volume of an object with a mass of 25 kg and a density of 5 g/mL.