Today’s Agenda11/2/15

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 timesLength 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 timesLength 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 TableCube

MaterialLength

(cm)Volume

(cm3)L x W x H

Mass (g)

Density (g/cm3)

Sinkor

Float

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

Data TableCube

MaterialLength

(cm)Volume

(cm3)L x W x H

Mass (g)

Density (g/cm3)

Sinkor

Float

Pine 2.5 cm 9 g

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

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 TableCube

MaterialLength

(cm)Volume

(cm3)L x W x H

Mass (g)

Density (g/cm3)

Sinkor

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 TableCube

MaterialLength

(cm)Volume

(cm3)L x W x H

Mass (g)

Density (g/cm3)

Sinkor

Float

Pine 2.5 cm 15.6 cm3 9 g 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 Agenda11/3/15

1. Turn in Density Cube Lab Graphic

Organizer2. 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!

Cube A

Length: 3.5 cm

Mass: 15 g

Length: 3.5 cm

Mass: 56 g

Cube B

Density :_______________ Density :_______________

Volume = 3.5 cm x 3.5 cm x 3.5 cm = 42.9 cm3

Density = Mass/ Volume

0.35 g/cm3 1.3 g/cm3

What happens when you drop the cubes in water?

Cube A

Density :_______________

Cube B

Density :_______________

water

0.35 g/cm3 1.3 g/cm3

A

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?

B. What lab equipment did the student use to measure the length?

C. What is the volume of the cube?

D. What is the density of the cube?

Triple Beam Balance

Ruler

V= l x w x hV= 3 X 3 x 3 = 27 cm3

D = mass/volumeD = 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?

B. What is this method of determining volume called?

C. If the mass of the seashell is 8 grams, what is the density of the seashell?

74 mL – 50 mL = 24 mL

Displacement

D = mass/volumeD = 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.

B. Draw what the liquids would look like in the container below. Label your drawing.

The liquids would separate.Liquid 1

Liquid 2

Liquid 3

0.3 g/mL1.0 g/mL

1.8 g/mL

#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.

Liquid 1

Liquid 2

Liquid 3

0.3 g/mL1.0 g/mL

1.8 g/mL

You have two cubes of copper. Does the size of a particular material affect its

density?

Small Cube

• Mass = 10 g• Volume = 5 cm3

Large Cube

• Mass = 20 g• Volume = 10 cm3

What is the density of each cube?

2.0 g/cm3 2.0 g/cm3

Today’s Agenda11/4/15

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

TuesdayReading 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 PropertyA.B.C.

For 2nd PropertyA.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.