1. Tuesday, August 26, 2014: Get out homework, for self check.
Have notebooks ready to take notes
Make sure you are in lab attire, BEFORE class begins.
Lab after notes
After Lab complete the post lab/homework

2. Density

3. The amount of matter in any given space.
What is density?
The amount of matter in any given space.
Density of a substance remains the same no matter how much of the substance is present making it a quantitative property.
*Density can only be an identifying property for a gas if the pressure and temperature are known.

4. How is density calculated?
It is a calculated physical property of matter that is derived from measurements of mass and volume.
It is mass divided by volume
Density = mass
volume
Density = g/mL

5. Complete the following practice problems in your notebook.

6. Let’s try a practice problem:
A sample of metal has a mass of 5.4 grams and a volume of 2.0 mL. What is the density of the sample?
Density = 5.4g/2.0mL = 2.7 g/mL

7. Can I solve for volume or mass if I know the density?
If the density of a post-1982 penny is approximately 6.94 g/mL and the mass is 2.5 g, what is the volume of the penny?
Volume=mass/density
___mL = 2.5 g / 6.94 g/mL
*The density of pure copper is 8.96 g/mL. Based on the information from above, is a penny made of pure copper? Why or why not?

8. Density Lab: You will work in groups of 3-4
Each person needs to complete their own lab
You will conduct 3 trials on 1982 and older pennies
You will conduct 3 trials on 1983 and newer pennies
WHEN ADDING PENNIES TO THE GRADUATED CYLINDER DO SO VERY SLOWLY AND CAREFULLY!!!!!!
Record data in data table
Once all data is collected return to your seats and begin completing the write up part of the lab.

9. Lab Safety Reminder: What are we working with today?
Do you need to wear goggles today, if so why?
What do you do if you break glass?
What do you do if you are uncertain about a step?

10. Post Lab/Homework:
Complete the density practice problems that were passed out at the beginning of class.
Due Friday before the test.
Your entire Unit 1 Assignment Packet is due Friday, August 29. (That’s this Friday)

11. Procedures
Obtain pennies from your teacher (I would recommend only 1 set at a time, to prevent mixing them up)
Obtain the mass of the pennies
Turn on the balance with NOTHING on it
Hit the tare/on button again to bring it to zero
Add 5, 10, or 15 pennies
Record the mass in the proper location of the data table
Add water to the graduated cylinder to the 50mL mark
Read the volume of the water alone (estimate the 10th’s place)
SLOWLY and CAREFULLY add the pennies
Read the volume of the water with the pennies (estimate the 10th’s place)
Use the water displacement method to calculate the volume
volume with pennies – volume without pennies = the volume of the pennies
Carefully dump the water and pennies out.
BE EXTRA CAREFUL NOT LET THE PENNIES GO DOWN THE DRAIN!
Repeat each step until you have completed all 3 trials with the 1982 and older pennies and all 3 trials with the 1983 and newer pennies.