Station 1: Determining the density of tap water Problem: How can we determine the density of water? Materials: 10 mL graduated cylinder, triple beam balance/scale, tap water, calculator Procedure: 1. Create your data table.

Use the correct number of significant figures. (Remember the rule!)

2. Measure the mass of an empty graduated cylinder. Record the mass. 3. Fill the cylinder with water to the 10 mL line. This is the volume. 4. Measure the mass of the cylinder with water. 5. Subtract the mass of the empty cylinder from the mass of the filled cylinder. 6. Divide the mass of the water by its volume. This will yield the density of the tap water. Record your result. 7. Repeat this experiment one time and calculate the average density of tap water. 8. Using the average density, calculate your experiment’s percent error, using 1.00 g/mL as your true/accepted value. This is the density of pure water. It’s a standard that would be good to memorize.

Station 2: Density of Four Metals Problem: How can we determine the density of four different types of metals? Materials: 4 metal cubes, ruler (in cm), triple beam balance/scale, calculator 1. Develop your own procedure to determine the density of the five types of metals. List the steps in your Science Journal. 2. Draw a data table and show your calculations in your Science Journal. 3. List the metals from least dense to most dense.

Use the correct number of significant figures. (Remember the rule!)

Station 3: Finding Density of an Irregular Object Problem: How do we determine the density of an irregular object? Materials: triple beam balance/scale, graduated cylinder, water, 4 non-uniform objects Procedure: 1. Create your data table.

Use the correct number of significant figures. (Remember the rule!)

2. Use the balance to find the mass of the object. Record the value on your data table. 3. Pour water into a graduated cylinder up to an easily-read value, such as 50 mL and record the volume. 4. Drop the object into the graduated cylinder and record the new value in mL. 5. The difference between the two numbers is the object's volume. Remember that 1 ml is equal to 1 cm3 6. Record the volume on the data chart. Compute the density of the object by dividing the mass value by the volume value. Record the density on the data chart. Conclusion: Describe an experiment that would be a more accurate method to determine the densities of these irregular objects.

Station 4: Intensive and Extensive Properties Problem: How can we determine whether density is an intensive or extensive property? Remember: Intensive properties do not change with size, while extensive properties do change with size.

Hypothesis: Write down your hypothesis before beginning. Materials: triple beam balance, graduated cylinder, water, 2 small balls of clay, 2 medium balls of clay Procedure: 1. Create your data table.

Use the correct number of significant figures. (Remember the rule!)

2. Use the balance to find the mass of the small ball of clay. Record the value on your data table. 3. Pour water into a graduated cylinder up to an easily-read value, such as 50 mL and record the volume. 4. Drop the ball of clay into the graduated cylinder and record the new value in mL. 5. The difference between the two numbers is the ball’s volume. Remember that 1 mL is equal to 1 cm3. 6. Record the volume on the data chart. Compute the density of the object by dividing the mass value by the volume value. Record the density on the data chart. 7. Repeat steps 2-5 for the remaining balls of clay. Data Table: Create your own in your Science Journal. Conclusion: Was your hypothesis valid or invalid? Is density an intensive or extensive property? Why?

Station 5: Determining the Viscosity of Liquids Problem: Which of the liquids is the least viscous? Which is the most viscous? Hypothesis: Write down your hypothesis before beginning. Materials: Viscosity Tubes, ruler (in cm), stopwatch Procedure: 1. Create your data table. 2. Measure the distance from the tip of the viscosity tube to the base of the rubber stopper that touches the liquid. 3. Invert the tube so the marble begins to travel down the length of the tube, while your lab partner starts the stopwatch. 4. When the marble hits the rubber stopper, stop the time. 5. Calculate the speed in cm/s. Repeat the trial and determine the average speed in cm/s. 6. Repeat steps 2-5 for the remaining liquids. Data Table: Create your own in your Science Journal. Make sure to indicate which liquid was the most viscous and which was the least viscous. Use the correct number of significant figures. (Remember the rule!)

Station 6: Density Practice Solve each of the problems below. Do not write the problems, but do SHOW YOUR WORK. Use the following equations to help you: Density = ______Mass (g)______ Volume (cm3 or mL)

1. What is the density of an object with a mass of 60 g and a volume of 2 cm3? 2. You are given the following information: mass = 48 g; volume=24 cm3. What is the density of this substance? 3. If you have a rectangular gold brick that is 2 cm by 3 cm by 4 cm and has a mass of 48 g, what is its density? 4. Bob, who weighs 150 pounds, found a rock. What is the density of a rock if its mass is 36 g and its volume is 12 cm3? 5. If a block of wood has a density of 0.6 g/cm3 and a mass of 120 g, what is its volume? 6. What is the mass of an object that has a volume of 34 cm3 and a density of 6 g/cm3? Use the correct number of significant figures. (Remember the rule!)

Station 7: Buoyancy Problem: What modifications can be made to a ball of clay to make it float in water? Hypothesis: _______________________________________________________ Materials: tray with water, 1 ball of clay, pennies Procedure: 1. Roll the clay into a round ball. 2. Carefully place it into the tray with water. Does it float? a. If the ball floats, record the number of pennies it can hold before it sinks. 3. Modify the shape of the clay. Does it float? a. If the ball floats, record the number of pennies it can hold before it sinks. 4. Repeat step 3 with one more shape and complete your data table. Data Table: Shape of Clay (Sketch)

Sink or Float?

Number of Pennies Held

Observations

Conclusion: Which shape was most buoyant? Which was least buoyant? How does buoyancy relate to density? Elaborate. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________