Density and other clues that identify a substance

Answer Key - Grade 8 Science Worksheet

Circle the best answer, or write your answer on the line.

1. 1.

   An ice cube has a mass of 18.4 g and a volume of 20 cm³. What is its density, Ari?

   0.92 g/cm³
2. 2.

   An oak block has a mass of 36 g and a volume of 50 cm³. What is its density, Bo?

   0.72 g/cm³

3. Read this first

   Density reference table (real data, rounded; NIST and Engineering ToolBox) (real data, rounded)

   substance	density (g/cm³)
   cork	0.2 to 0.25
   oak wood	0.72
   olive oil	0.91
   ice	0.92
   corn oil	0.92
   water	1
   sea water	1.025
   aluminum	2.7
   zinc	7.13
   iron	7.87
   copper	8.96
   silver	10.5
   gold	19.3

4. 3.

   A mystery metal has a mass of 54 g and a volume of 20 cm³. Using the table, what is it, Jun?

   • Zinc
   • Aluminum
   • Iron, since it is a heavy block
   • Copper
5. 4.

   A mystery metal has a mass of 157.4 g and a volume of 20 cm³. Using the table, what is it, Kira?

   • Zinc
   • Gold, since it is heavy
   • Iron
   • Copper
6. 5.

   A mystery metal has a mass of 105 g and a volume of 10 cm³. Using the table, what is it, Luz?

   • Copper
   • Iron
   • Gold, since it is the heaviest
   • Silver

7. Use this

   Jar of two liquids that do not mix (real densities, rounded): water 1.00 g/cm³ and corn oil 0.92 g/cm³, poured in and left to settle.

9. 6.

   Milo's class lets the water and corn oil settle. Which liquid ends up on top?

   • Corn oil
   • Water, since there is more of it
   • Neither; they mix evenly
   • Whichever was poured in last
10. 7.

    Noah drops a small oak block into the jar. Where does it end up?

    Use the picture in question 6.

    • Floating on top of the corn oil
    • At the bottom, since wood is heavy
    • At the bottom of the water
    • Between the oil and the water
11. 8.

    An acrylic plastic bead has a density of 1.19 g/cm³. Where does it settle in the jar, Pia?

    Use the picture in question 6.

    • On top of the oil, since it is small
    • At the bottom, under the water
    • Between the oil and the water, since it is light
    • On top of the oil, since plastic floats
12. 9.

    Ren cuts a copper bar (8.96 g/cm³) in half. What is the density of one half?

    • 4.48 g/cm³, half as much
    • 8.96 g/cm³
    • 17.92 g/cm³
    • Less, since a half weighs less
13. 10.

    Zee pours half the water out of a glass. What is the density of the water left?

    • About 0.50 g/cm³
    • About 1.00 g/cm³
    • Less, since there is less of it
    • About 2.00 g/cm³