1. During a Lesson
Put all phones and other electronic devices away. (iPads will be discussed in a minute.)
No talking or noise-making.
Stay seated at all times (unless you are dying.)
Participate when asked.
Keep your head up and stay focused.
Raise your hand if you have a question RELATED to the current lesson. (Personal problems are addressed later.)

2. Catalyst 9/19/12 Grab a Catalyst sheet and answer the following.
Kevin wants to measure the volume of his computer. What unit will he use to measure it?
What is the SI standard unit for mass?
What is the SI standard unit for temperature?
Give 2 examples of applied research and basic research.

3. Agenda 9/19/12 Catalyst (4 minutes) Density Lesson (20 minutes)
Class Practice (15 minutes)
Student Job Assignments (3 minutes)
Text Message Set Up (1 minute)
Exit Slip (4 minutes)

4. OBJECTIVE(S) We will be able to: Perform density calculations.
Determine whether an object will sink or float in a fluid.

5. Definition of Density
Density: the ratio of mass to volume (in other words, mass divided by volume)
What’s mass?
What’s volume?

6. Density: the ratio of mass to volume (in other words, mass divided by volume)
What’s mass? The measurement of the amount of matter
What’s volume?

7. Density: the ratio of mass to volume (in other words, mass divided by volume)
What’s mass? The measurement of the amount of matter
What’s volume? How much space something takes up

8. Compare Thing 1 and Thing 2
Which of these has more matter (mass)?
Which has more space (volume)?
So which one is the most dense?
Thing 1
Thing 2

9. Compare Thing 1 and Thing 2
Matter/ Matter/
Space Space
Less dense
Thing 1
Thing 2
More dense

10. Compare Thing 3 and Thing 4
Which of these has more matter?
Which has more space?
So which one is the most dense?
More dense
Thing 4
Thing 3
Less dense

11. Formula for Density
Density = mass = g or g volume mL cm3 1 milliliter (mL) = 1 cubic centimeter (cm3)

12. Even though the kilogram (kg) and cubic meter (m3) are the STANDARD SI Units, it’s more convenient to use grams and cubic centimeter (or milliliter) in the laboratory.

13. Density Problem Example#1
Osmium is a very dense metal. What is its
density if g of the metal occupies
a volume of 2 cm3?
lecturePLUS Timberlake

14. lecturePLUS Timberlake
Solution
D = mass = g =
volume 2.00 cm3
= 25 g/cm3
lecturePLUS Timberlake

15. Other types of density calculations…

16. Density Problem Example#2
The new iPhone 5 has a density of 2.03 g/cm3 and a mass of 112 grams. What is its volume?

17. YOU TRY!
On your whiteboards, answer the following: The Samsung Galaxy S III, which Apple tried to ban, has a density of 1.64 g/cm3. If the digital balance reads 133 g, what is its volume?

18. Density Problem Example#3
The chicken nuggets in the cafeteria has a density of g/cm3 and a volume of 15 cm3. Calculate its mass.

19. YOU TRY!
The carton of milk from Rite Aid has a density of g/mL. If you are given 150 mL of milk, what mass of the milk do you have?

20. Density is considered to be a physical property of a substance.

21. Sink or float?
If an object’s density is GREATER than the density of water (1.00 g/cm3), it will SINK in water.
If an object’s density is LESS than the density of water (1.00 g/cm3), it will FLOAT on water.

22. Student Jobs!
Earn 20% additional points in your packet participation grade. (If you were supposed to receive 100 points, you’ll receive 120 points instead!) And 3 points extra on your Weekly Catalyst grade.
**If you violate a classroom policy, you will NOT receive your extra credit!
You will keep this job for at least one month (or less if you get fired).

23. Student Jobs!
(2) Class Maintainer: Makes sure that classmates pick up their trash and push their chairs in.
(1) Calculator Manager: Collects all calculators. (Count them!)
(1) Whiteboards Manager*: Collects whiteboards and ensures they are blank.
(1) Markers Manager*: Collects all markers (Count them!)
(1) Catalyst Collector: Collects Catalyst or other papers.
(2) Paper Passer: Quickly returns graded work to students.
(1) Technical Assistant: Helps set up projector and laptop if Mr. Gutierrez is running late.

24. Text Messaging Reminders and Edmodo
Take out your cell phones and text cpchemp to
Have access to a computer? Join the AOF Chemistry group. The code is ozm60q. (If you join the group by Friday, I will give you extra 5 points on your Catalyst grade for the week.)

25. Exit Slip Answer on a half sheet of paper.
An object has a mass of 100 grams and a volume of 25 cm3. Calculate its density. Show ALL your work.
If an object is LESS dense than water, will it FLOAT or SINK?
If an object is MORE dense than water, will it FLOAT or SINK?