http://phet.colorado.edu/
Neutral Boron Atom:
Proton: 5
Neutrons: 5
Electrons: 5
Density: 2.34 g/cm3
Neutral Lithium Atom:
Proton: 3
Neutrons: 3
Electrons: 3
Density: 0.534 grams per cubic centimeter
2. Define density and the equation for density.
According to our class book, Chemisty for Changing Times by John Hill, density is the quantity of mass per unit volume. The equation of density is mass divided by volume or simply d=m/v.
3. Run the Density simulation http://phet.colorado.edu/en/simulation/density and complete one of the prepared Teaching Ideas.
I preformed the Density and Bouyancy lab by Milton Johnson and completed the worksheet (which is below in gray).
PhET- Density
Activity- Funsheet
Custom Section
Name: Taylor Molitor
Material
|
Mass (kg)
|
Volume (L)
|
Density (kg/L)
|
Does it Float?
|
Styrofoam
|
.75kg
|
5.00L
|
0.15kg/L
|
Yes
|
Wood
|
2.00kg
|
5.00L
|
0.40kg/L
|
Yes
|
Ice
|
4.60kg
|
5.00L
|
0.92kg/L
|
Yes
|
Brick
|
10.00kg
|
5.00L
|
2.00kg/L
|
No
|
Aluminum
|
13.50kg
|
5.00L
|
2.70kg/L
|
No
|
1.
In the custom setting, choose the ‘My Object’
option in the material drop down box. Set
the mass of your object to 4 kg. Adjust
the volume to find the minimum volume needed to make the object float.
Volume: 4.01L Density: 1.00kg/L
2.
How does the density of a large piece of aluminum
compare to a small piece?
It’s the same density no matter the size of the aluminum.
Same Mass Section
Material
|
Mass (kg)
|
Volume (L)
|
Density (kg/L)
|
Does it Float?
|
Blue
|
5.00kg
|
5.00L
|
1.00kg/L
|
No
|
Yellow
|
5.00kg
|
5.00L
|
1.00kg/L
|
Yes
|
Green
|
5.00kg
|
2.50L
|
2.00kg/L
|
No
|
Red
|
5.00kg
|
1.25L
|
4.99kg/L
|
No
|
Same Volume Section
Material
|
Mass (kg)
|
Volume (L)
|
Density (kg/L)
|
Does it Float?
|
Blue
|
6.00kg
|
5.00L
|
1.20kg/L
|
No
|
Yellow
|
8.00kg
|
5.00L
|
1.60kg/L
|
No
|
Green
|
4.00kg
|
5.00L
|
0.80kg/L
|
Yes
|
Red
|
2.00kg
|
5.00L
|
0.40kg/L
|
Yes
|
3. Looking at the
data on the previous page, what must be true about the density of
an object in
order for it to float?
In order for the object to float, the density of the object
must be less then 1.00kg/L and sometime equal to that.
Same Density Section:
4. Calculate the
density of the blue object in this section.
Mass ____3.00kg______ Volume____3.00L_______ Density_____1.00kg/L_______
5. Explain why both
the yellow and red objects float when they have different sizes.
Both of these objects float because both of them have a
density equal to 1.00kg/L.
Mystery Section:
6. Before you start,
pick an object that you think will float.
______Object B___________
Pick an object
that you think will sink. ________Object
E__________
Material
|
Mass (kg)
|
Volume (L)
|
Density (kg/L)
|
Does it Float?
|
A
|
64.14kg
|
3.38L
|
18.98kg/L
|
No
|
B
|
0.64kg
|
0.64L
|
1.00kg/L
|
Yes
|
C
|
4.08kg
|
4.08L
|
1.00kg/L
|
Yes
|
D
|
3.10L
|
3.10L
|
1.00kg/L
|
Yes
|
E
|
3.53kg
|
1.00L
|
3.53 kg/L
|
No
|
7. In the Custom
section describe the difference between how Styrofoam and ice
floated. Also explain why you think this is the case?
In the custom section, the ice floated but was mostly under
the water, while the Styrofoam was floating mostly on top of the water. I think
this is because even though they have the same density, the ice is more of a
solid object while Styrofoam has more air in it. Styrofoam also has less of a
volume then ice does.
8. In the Same Mass
Section discuss what was interesting about the blue object’s behavior in the
water.
The blue object did not float at the surface of the water,
but if you drug it into the middle of the water and let go it would sit
wherever you put in under the water.
9. In the Mystery
Section, click on the “Show Table” button.
What is the most dense
object on the
list? Write its density as well.
The most dense object in the mystery section is a piece of
gold and it’s density is 19.3kg/L
10. List something
you learned from this activity.
In this activity, I learned that in ordered for something to
float, it’s density needs to be less than or equal to 1.00, but even when the
density of an object is 1.00 it still may not float above water, like in the
same mass section with the blue object.
4. Complete the Mystery Blocks activity on the Density simulation. Post on your blog the data you collected (mass, volume, and density) and the identification of the material and the known density.
Object Mass Volume Density Identification Known density
(Based on table)
Object A: 64.14kg 3.38 L 18.98kg/L Gold 19.30 kg/L
Object B: 0.64 kg 0.64 L 1.00 kg/L Water 1.00 kg/L
Object C: 4.08 kg 4.08 L 1.00 kg/L Water 1.00 kg/L
Object D: 3.10 kg 3.10 L 1.00 kg/L Water 1.00 kg/L
Object E: 3.53 kg 1.00 L 3.53 kg/L Diamond 3.53 kg/L
5. Identify the Science Standards that could be met through these activities completed.
This experiment meets a few different Science Standards of Wisconsin for a fourth grader. These standards are:
- B.4.1 Use encyclopedias, source books, texts, computers, teachers, parents, other adults, journals, popular press, and various other sources, to help answer science-related questions and plan investigations
- C.4.2 Use the science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations
- C.4.4 Use simple science equipment safely and effectively, including rulers, balances, graduated cylinders, hand lenses, thermometers, and computers, to collect data relevant to questions and investigations
- C.4.5 Use data they have collected to develop explanations and answer questions generated by investigations
