Name:_______________________
Period:_________________
Density Simulation
Pre-lab Questions:
1. What is mass?
2. What is volume?
3. What equation do we use to calculate density?
4. In your own words give a definition of density (do not give me the definition from your notes).
Go to the PhET simulation of density by typing in this web address:
http://phet.colorado.edu/sims/density-and-buoyancy/density_en.html
or Google Search PhET, choose Chemistry simulations, choose density, click Run Now
Activity 1
On the first screen you have two options, you can choose “my block” or you can choose “material”, start off
with “material”. In the drop down menu you can change the material that the block in the water is made of.
There is a scale that tells you the density of the material.
1. Which of the materials float in the water and which of them sink? (sink means goes ALL the way to the
bottom)
2. What does the density of all the materials that float have in common? (use science terms and DO NOT
tell me that they are lighter or weigh less)
3. There are two sliders, one for mass and the other for volume, why when you move one of them do
both the numbers for mass and volume change?
Activity 2
Now change to “my block”, find a mass and volume that gets the block to stay even with the surface of the
water (not sticking up out of the water and not sinking to the bottom)
4. What mass and volume did you choose? (don’t forget units)
Mass = ___________
Volume= ___________
5. What is the density of your block? (don’t forget units)
Density = ____________
6. Why do you think the block floats just underneath the water, but doesn’t sink to the bottom?
Activity 3
On the right hand side of the screen change the setting from “Custom” to “Same Mass”. There are four blocks
that appear red(the smallest), green, blue, and yellow (the largest). You can move each of these blocks in an
out of the water.
7. List the order of the blocks from smallest density to largest density. Use what you know about the
mass/volume relationship to do this.
Activity 4
Now on the right hand side change the setting to “Same Volume”, this time all of the blocks are the same size
but they have different masses. You again can move the boxes in and out of the water.
8. List the order of the blocks from smallest to largest density. (same as #7)
Activity 5
Now on the right hand side change the setting to “Same Density”.
9. Which of the block sink and which float? Why does this make sense?
Activity 6
Lastly, you will change the setting on the right hand side to “Mystery”. In this section you are able to obtain
the mass of each block by putting it on the scale and can place the blocks in the water. To find the volume of
your blocks using water displacement make sure to drag the blocks all the way to the bottom of the water.
Your job is to identify the material that each block is made out of based on the density you find and the table
provided. You can see the table by clicking on the “Show Table” tab on the right hand side of the screen. Fill in
the chart below.
Block
A
B
C
D
E
Mass (kg)
Volume (L)
Density (kg/L)
Material
(Click on show table
middle right side)