Density: Reflect and Review

Target: I can find the mass, and volume of various objects and calculate the

density of those objects.

How do you find density?

• Explain how to find the density of these objects. Include the steps, units, and how to calculate it.

Reflection: Name that Substance

• How did you find the density of the rods at this station?

• Were you able to find out what the substance actually was by finding the density? Why or why not?

• What are some practical applications of finding the density of things when you don’t know exactly what they are?

Reflection: Sink or Float

• How can you prove an object will sink, or float without actually putting it in water and testing it?

• Can the sink/float density rule be broken? Why or why not?

Reflection: The Density Challenge

• Describe how you/your group tried to solve the Density Challenge?

• Answer: Purple, Blue, Yellow, Green• How did you knowledge of what liquids of

different densities do when you combine them help you?

Reflection: The Three Liquids

• You collected data to prove that your three liquids would layer according to their densities. What was it?

• How did you calculate the densities of the liquids? How is this different from solids?

Reflection: Density Blocks and Density Rods

• What were some observations you made about the blocks and the rods?

• The density blocks are an excellent tool for illustrating differences in density. Why?

Practice

• Mass/Volume=Density• g/cm3

• 1 mL= 1cm3

• Volume of a rectangular solid: LxWxH• Volume of an irregular solid: Water

displacement method

Practice

1) A block of aluminum occupies a volume of 15.0 mL and weighs 40.5 g. What is its density?

2) Mercury metal is poured into a graduated cylinder that holds exactly 22.5 mL. The mercury used to fill the cylinder weighs 306.0 g. From this information, calculate the density of mercury.

3. A rectangular block of copper metal weighs 1896 g. The dimensions of the block are 8.4 cm by 5.5 cm by 4.6 cm. From this data, what is the density of copper?

4. A block of lead has dimensions of 4.50 cm by 5.20 cm by 6.00 cm. The block weighs 1587 g. From this information, calculate the density of lead.

5. 28.5 g of iron shot is added to a graduated cylinder containing 45.50 mL of water. The water level rises to the 49.10 mL mark, from this information, calculate the density of iron.

Sing Along!

• http://www.youtube.com/watch?v=FSupQZQqaPk

• http://www.youtube.com/watch?v=kZhCHezow_Y

• http://www.youtube.com/watch?v=-f5FBvtJ7T0