Names:

Computer Lab Density Activity

Introduction: Density is a physical property of matter that is calculated by dividing the mass of an object by its volume. Volume can be computed for a regular object by multiplying length x width x height. Another way to compute volume is by submerging an object into a liquid. You must record the starting volume of the liquid and the final volume after the object has been submerged. Then subtract the starting volume from the final volume.

Procedure:

  • Open the internet browser and enter the address:
  • Click on “Play with Sims” and select “Chemistry” from the menu on the left.
  • Open the “Density” Simulation and select “Run Now”

Objectives:

  • Describe how the concept of density relates to an object's mass and volume.
  • Explain how objects of similar mass can have differing volume, and how objects of similar volume can have differing mass.
  • Measure the volume of an object by observing the amount of fluid it displaces.
  • Identify an unknown material by calculating its density and comparing to a table of known densities.

On the top left side of the computer screen… explore different materials with different masses and different volumes. Experiment with (click on) Material, then answer the following questions.

a. Which materials sink?

______

b. Which materials float?

______

c. Keep exploring …

What does the label “Volume” mean?

______

What does the label “Mass” means?

______

d. Explore what happens when you make the block(s) bigger and smaller.

Does the Mass change? ______

Explain why: ______

Does the Density change? ______

Explain why: ______

Does the floating or sinking change?

______

Design your own block!

Experiment with making your own block out of your own material - clickMy Block.

What properties of the block can you change?

______

What makes a block more likely to sink? How does this change the block’s density?

______

What makes a block more likely to float? How does this change the block’s density?

______

Try to create a block with a very HIGH density.

Do you think your blockwill sink or float? ______

What is your block’s volume? ______What is your block’s mass? ______

Try to create a block with a very LOW density.

Do you think your blockwill sink or float? ______

What is your block’s volume? ______What is your block’s mass? ______

Investigate:

  1. On the Blocks menu (top right) select Same Mass.
  2. One at a time, take a block, lower it into the liquid, and record its volume. If it floats, you will need to hold it under the water to record its volume.
    Then use a calculator and compute each block’s density.

Blue:mass 5 kg kg/L

volume L

Yellowmass

volume

Greenmass

volume

Redmass

volume

  1. Repeat for Same Volume.

Blue:mass kg kg/L

volume 5 L

Yellowmass

volume

Greenmass

volume

Redmass

  1. Repeat for Same Density

Blue:mass

volume

Yellowmass

volume

Greenmass

volume

Redmass

  1. Repeat for Mystery. This time you will also have to take the mass of each object. After computing the density, select Show Tableand identify each object.

IDENTIFICATION

A:mass

volume

Bmass

volume

Cmass

volume

Dmass

Emass