Activity 4: Density 

1. Run the Build an Atom simulation and build a neutral lithium atom and a neutral boron atom. Take a picture, or a screen shot, of these two atoms. List the number of protons, neutrons and electrons for each. Also look up and post the density for each of the elements on your blog.

o   Lithium: 3 Protons, 4 Neutrons, 3 Electrons, Density is .53g/cm3

o   Boron: 5 Protons, 6 Neutrons, 5 Electrons, Density is 2.34 g/cm3

2. Define density and the equation for density.

o   The density of a substance is the quantity of mass per unit of volume. D=M/V

3. Run the Density simulation and complete one activity of the prepared Teaching Ideas and post results.

 Name: Ashley Weimar

Density

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:  http://phet.colorado.edu
• 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.

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 compute each block’s density.

Blue:      Mass is 5kg

                Volume is 5L

                =1kg/L

Yellow: Mass is 5kg

                Volume is 10L

                =.5kg/L

Green:  Mass is 5kg

                Volume is 2.50L

                = 2kg/L

Red:       Mass is 5kg

                Volume is 1.25

                =4kg/L

3.       Repeat for Same Volume.

Blue:      Mass is 6kg

                Volume is 5L

                =1.2kg/L

Yellow: Mass is 8kg

                Volume is 5L

                =1.6kg/L

Green:  Mass is 4kg

                Volume 5L

                =.8kg/L

Red:       Mass is 2kg

                Volume is 5L

                =.4kg/L

4.       Repeat for Same Density

Blue:      Mass is 3kg

                Volume is 3.75L

                =.8kg/L

Yellow: Mass is 4kg

                Volume is 5L

                =.8kg/L

Green:  Mass is 2kg

                Volume is 2.50

                =.8kg/L

Red:       Mass is1kg

                Volume is 1.25L

                =.8kg/L

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

IDENTIFICATION

A:            Mass is 65.14 kg                                                                         Gold

                Volume is 3.38L

                =19.27kg/L

B:            Mass is .64kg                                                                              Apple

                Volume is 1L

                =.64kg/L

C:            Mass is 4.08kg                                                                         Gasoline

                Volume is 5.83L

                =.70kg/L

D:            Mass is 3.10kg                                                                              Ice

                Volume is 3.38L

                =.92kg/L

E:            Mass is 3.53kg                                                                           Diamond

                Volume is 1L

                =3.53kg/L

                

  4. (mass, volume, and density) and the identification of the material and the known density.

o   Gold

·   Mass: 65.14kg

·   Volume: 3.38L

·   Density: 19.27kg/L

o   Apple

·   Mass: .64kg

·   Volume: 1L

·   Density: .64kg/L

o   Gasoline

·   Mass: 4.08kg

·   Volume: 5.83L

·   Density: .70kg/L

o   Ice

·   Mass: 3.10kg

·   Volume: 3.38L

·   Density: .92kg/L

o   Diamond

·   Mass: 3.53kg

·   Volume: 1L

·   Density: 3.53kg/L

5.    Identify the Science Standards that could be met through these activities.

o   A.4.1 When conducting science investigations, ask and answer questions that will help decide the general areas of science being addressed.

o   C.4.5 Use data they have collected to develop explanations and answer questions generated by investigations.

o   C4.6 Communicate the results of their investigations in ways their audiences will understand by using charts, graphs, drawings, written descriptions,  and various other means, to display their answers.

o   C8.8 Use computer software and other technologies to organize, process, and present their data.