Revisit Density Cube Lab Redo Density Lab – Due TOMORROW Today’s Agenda 11/2/15 Check out the FULL Hunter’s Moon! The moon will rise close to the time of sunset for a few evenings! Revisit Density Cube Lab -------------------------------- Redo Density Lab – Due TOMORROW

Density Cube Lab

Relative Density

Pre-lab Questions 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 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

Measure the Mass by using a Triple Beam Balance (TBB) Pre-lab Questions 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)

Divide the cube’s mass by the cube’s volume. Pre-lab Questions 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 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 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 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) L x W x H Mass (g) Density (g/cm3) Sink or Float Copper 2.5 cm 145 g Oak 10 g Nylon 18 g PVC 21.4 g Aluminum 45.3 g

Data Table Cube Material Length (cm) Volume (cm3) L x W x H Mass (g) Density (g/cm3) Sink or Float Pine 2.5 cm 9 g Poplar 6.9 g Brass 136.9 g Steel 127.9 g Acrylic 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 Table Cube Material Length (cm) Volume (cm3) L x W x H Mass (g) Density (g/cm3) Sink or Float Copper 2.5 cm 15.6 cm3 145 g 9.3 g/cm3 Oak 10 g 0.64 g/cm3 Nylon 18 g 1.2 g/cm3 PVC 21.4 g 1.4 g/cm3 Aluminum 45.3 g 2.9 g/cm3

Data Table Cube Material Length (cm) Volume (cm3) L x W x H Mass (g) Density (g/cm3) Sink or Float Pine 2.5 cm 15.6 cm3 9 g 0.6 g/cm3 Poplar 6.9 g 0.4 g/cm3 Brass 136.9 g 8.8 g/cm3 Steel 127.9 g 8.2 g/cm3 Acrylic 19.2 g 1.2 g/cm3

Today’s Agenda 11/3/15 Turn in Density Cube Lab Graphic Organizer 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 B Cube A Volume = 3.5 cm x 3.5 cm x 3.5 cm = 42.9 cm3 Length: 3.5 cm Mass: 15 g Length: 3.5 cm Mass: 56 g 0.35 g/cm3 1.3 g/cm3 Density :_______________ Density :_______________

What happens when you drop the cubes in water? Cube A Density :_______________ Cube B Density :_______________ 0.35 g/cm3 1.3 g/cm3 A water B

#1. The mass of a cube is 36 grams and its length is 3 cm. What lab equipment did the student use to measure the mass? What lab equipment did the student use to measure the length? What is the volume of the cube? What is the density of the cube? Triple Beam Balance Ruler V= l x w x h V= 3 X 3 x 3 = 27 cm3 D = mass/volume D = 36 g/ 27cm3 = 1.3 g/cm3

74 mL – 50 mL = 24 mL Displacement D = mass/volume #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. What is the volume of the seashell? What is this method of determining volume called? 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/volume D = 8 g/ 24 mL = 0.3 g/mL

When the student places the seashell in water. What happened 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.

The liquids would separate. #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. Explain what will happen to the liquids if you poured all three of them into a cylindrical container. Draw what the liquids would look like in the container below. Label your drawing. The liquids would separate. 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 #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. You drop a solid into the container that has a density of 1.2 g/mL. Explain what will happen to the solid. 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 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 Agenda 11/4/15 Turn in Chemical Observation Lab 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. 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. 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. 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 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.  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. 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. 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.