Today’s Agenda
11/2/15
Revisit Density Cube Lab
--------------------------------
Redo Density Lab – Due
TOMORROW
Check out the FULL
Hunter’s Moon!
The moon will rise close to
the time of sunset for a
few evenings!
Density Cube Lab
Relative Density
Pre-lab Questions
1. Explain how you find the volume of a
REGULAR solid.
Answer: Look at the procedure steps 3 & 4
Measure the length of one side of the cube
and multiply the SAME number by itself
three times
Length x Width x Height
Pre-lab Questions
2. Explain why it is easier to find the volume of
a cube than it is to find the volume of a
rectangular prism.
You ONLY need to measure the length of one
side of the cube and multiply the SAME
number by itself three times
Length x Width x Height
Pre-lab Questions
3. Explain how you find the MASS of a REGULAR
solid.
Answer: Look at the procedure step 2
Measure the Mass by using a Triple Beam
Balance (TBB)
Pre-lab Questions
4. Identify the density formula AND write out in
words what you must do to calculate density.
Answer: Look at the procedure step 5
Density = Mass
Volume
Divide the cube’s mass by the cube’s volume.
Pre-lab Questions
5. Look up the definition of density and write it
on the lines below.
Answer: Look in your SINK!
Density is the amount of mass in a given
amount of volume.
How compact an object’s matter is.
Pre-lab Questions
6. The cubes you will be using to calculate
density are made of different materials but
are the exact same size. Does this mean
they will have the same density? Explain.
Answer: Use your prior knowledge.
If they are the SAME size but made of
different materials, will they have the SAME
density?????
Pre-lab Questions
7. Using your answer to #6, write a hypothesis.
It MUST be in an “if, then, because” format.
If the cubes are the same size but are made
of different materials, then they will each
have ________________ densities
because……
Below a 75
OR
Not Happy with YOUR Score?
• Redo your data table AND write a
new conclusion.
• Separate sheet of paper.
• DUE Tomorrow!
Data Table
Cube
Material
Length
(cm)
Volume
(cm3)
LxWxH
Mass
(g)
Copper
2.5 cm
145 g
Oak
2.5 cm
10 g
Nylon
2.5 cm
18 g
PVC
2.5 cm
21.4 g
Aluminum
2.5 cm
45.3 g
Density
(g/cm3)
Sink
or
Float
Data Table
Cube
Material
Length
(cm)
Volume
(cm3)
LxWxH
Mass
(g)
Pine
2.5 cm
9g
Poplar
2.5 cm
6.9 g
Brass
2.5 cm
136.9 g
Steel
2.5 cm
127.9 g
Acrylic
2.5 cm
19.2 g
Density
(g/cm3)
Sink
or
Float
Conclusion
A. Restate the hypothesis.
B. Identify whether your hypothesis was
supported or not by your results.
C. Support your claim with evidence from the
lab.
D. Identify at least one change that could
improve the lab procedure.
E. Explain why that change would improve the
lab procedure.
Data Table
Cube
Material
Length
(cm)
Volume
(cm3)
LxWxH
Mass
(g)
Density
(g/cm3)
Sink
or
Float
Copper
2.5 cm
15.6 cm3
145 g
9.3 g/cm3
Sink
Oak
2.5 cm
15.6 cm3
10 g
0.64 g/cm3
Float
Nylon
2.5 cm
15.6 cm3
18 g
1.2 g/cm3
Sink
PVC
2.5 cm
15.6 cm3
21.4 g
1.4 g/cm3
Sink
Aluminum
2.5 cm
15.6 cm3
45.3 g
2.9 g/cm3
Sink
Data Table
Cube
Material
Length
(cm)
Volume
(cm3)
LxWxH
Mass
(g)
Density
(g/cm3)
Sink
or
Float
Pine
2.5 cm
15.6 cm3
9g
0.6 g/cm3
Float
Poplar
2.5 cm
15.6 cm3
6.9 g
0.4 g/cm3
Float
Brass
2.5 cm
15.6 cm3
136.9 g
8.8 g/cm3
Sink
Steel
2.5 cm
15.6 cm3
127.9 g
8.2 g/cm3
Sink
Acrylic
2.5 cm
15.6 cm3
19.2 g
1.2 g/cm3
Sink
Today’s Agenda
11/3/15
1. Turn in Density Cube
Lab Graphic Organizer
2. Practice with Density
--------------------------------
Major Celebration of
Knowledge NEXT Tuesday
Reading chemical formulas,
measuring matter & physical vs.
chemical changes
Calculate the density of each of the cubes below
and then draw what would happen to them if they
were dropped in a container of water. Explain why
you think this would happen. Don’t forget UNITS!
Density = Mass/ Volume
Cube A
Cube B
Volume = 3.5 cm x 3.5 cm x 3.5 cm = 42.9 cm3
Length: 3.5 cm
Length: 3.5 cm
Mass: 15 g
Mass: 56 g
0.35 g/cm3
Density
:_______________
1.3 g/cm3
Density
:_______________
What happens when you drop the
cubes in water?
Cube A
0.35 g/cm3
Density :_______________
Cube B
1.3 g/cm3
Density :_______________
A
water
B
#1. The mass of a cube is 36 grams
and its length is 3 cm.
A. What lab equipment did the student use to measure
the mass?
Triple Beam Balance
A. What lab equipment did the student use to measure
the length?
Ruler
l xw xh
A. What is the volume of the V=
cube?
V= 3 X 3 x 3 = 27 cm3
A. What is the density of the
D =cube?
mass/volume
D = 36 g/ 27cm3 = 1.3 g/cm3
#2. A student wants to find the density of a
seashell. The student places the seashell in a
graduated cylinder that contains 50 mL of water.
The water level rises to 74 mL.
A. What is the volume of the seashell?
74 mL – 50 mL = 24 mL
A. What is this method of determining volume called?
Displacement
A. If the mass of the seashell is 8 grams, what is the
density of the seashell?
D = mass/volume
D = 8 g/ 24 mL = 0.3 g/mL
D. When the student places the seashell in
water. What happened. Explain the
relationship between the density of the
seashell and the density of the water.
#3. You are given 3 liquids of different densities.
Liquid 1 has a density of 0.3 g/mL, Liquid 2 has a
density of 1.8 g/mL, and Liquid 3 has a density of
1.0 g/mL.
A. Explain what will happen to the liquids
if you poured all three of them into a
cylindrical container.
The liquids would separate.
A. Draw what the liquids would look like
in the container below. Label your
drawing.
0.3
g/mL
Liquid 1
1.0
g/mL
Liquid 3
1.8
g/mL
Liquid 2
#3. You are given 3 liquids of different densities.
Liquid 1 has a density of 0.3 g/mL, Liquid 2 has a
density of 1.8 g/mL, and Liquid 3 has a density of
1.0 g/mL.
C. You drop a solid into the container
that has a density of 1.2 g/mL.
Explain what will happen to the solid.
D. Draw and label the solid in the
cylinder.
0.3
g/mL
Liquid 1
1.0
g/mL
Liquid 3
1.8
g/mL
Liquid 2
You have two cubes of copper. Does
the size of a particular material affect
its density?
Small Cube
Large Cube
• Mass = 10 g
• Volume = 5 cm3
• Mass = 20 g
• Volume = 10 cm3
What is the density of each cube?
2.0 g/cm3
2.0 g/cm3
Today’s Agenda
11/4/15
1. Turn in Chemical
Observation Lab
2. Review Practice Open
Response Questions
---------------
3. Revisit the chemical
observation lab….What
happened?
Major Celebration of
Knowledge NEXT
Tuesday
Reading chemical
formulas, measuring
matter & physical vs.
chemical changes
1. The picture below shows a sample
of liquid in a graduated cylinder.
A. Identify what property of the sample is
being measured with the graduated
cylinder.
The property being
measured with the
graduated cylinder is
volume of a liquid.
1. The picture below shows a sample
of liquid in a graduated cylinder.
B. Identify the measurement of the sample in
the graduated cylinder. Include units!
The graduated cylinder
shows a measurement of
36.5 mL.
The entire sample was transferred to a
100 mL beaker, as shown below.
C. Identify the measurement of the sample in
the beaker. Include units.
The beaker shows a
measurement of 35 mL.
The entire sample was transferred to a
100 mL beaker, as shown below.
D. Explain why the measurements would
be recorded differently when the
sample is in the graduated cylinder and
when it is in the beaker.
The graduated cylinder is
used to get a more
accurate measurement
because it has more
intervals.
Practice Answering Open Response Questions
Topic Sentence
For 1st Property
A.
B.
C.
For 2nd Property
A.
B.
C.
Conclusion
Complete
Sentences!
2. Jorge was given the cube shown
below and asked to determine the
density of the cube. The material that
the cube is made from is unknown.
A. Identify the two properties of the cube
that must be known in order for Jorge to
determine the density of the cube.
The two properties that must be
known to determine the density of the
cube are mass and volume.
2. Jorge was given the cube shown below and asked to
determine the density of the cube. The material that the cube
is made from is unknown.
B. Describe how Jorge could measure each of the
properties of the cube you identified in part
(a). Be sure to identify any tools Jorge would
use and describe how he would use them.
Jorge can use a triple beam balance to measure the
mass of the cube. To determine the volume of the
cube, he could use a ruler to measure the length,
width and height of the cube and multiply them
together.
2. Jorge was given the cube shown below and
asked to determine the density of the cube. The
material that the cube is made from is unknown.
C. Explain how the measurements you
described in part (b) can be used to
determine the density of the cube.
The mass and volume of an object can be
used to determine the density of the
material. Density equals mass divided by
volume.