The layers inside the Earth

Grade 6 Science Worksheet

Circle the best answer.

1. 1.

   Bo compares two layers. Which is hotter: the mantle or the inner core?

   • The mantle, since it is made of lava
   • Both the same, since deep rock heats up evenly everywhere
   • The mantle, since it is closer to the Sun
   • The inner core, since heat rises with depth
2. 2.

   USGS says the core is nearly twice as dense as the mantle. Which reason does Esme give?

   • A drill sample from the core was weighed
   • It is iron and nickel metal under great pressure
   • It is cooler down there, so it packs together tighter
   • It is a liquid ocean of heavy lava
3. 3.

   Temperature, pressure, density. Temperature, pressure and density all change as you go deeper. Which pattern does Jun find in the USGS notes?

   • All three decrease with depth
   • Only temperature increases with depth
   • They peak in the mantle, then fall
   • All three increase with depth
4. 4.

   The crust is about 5 km thick under oceans and about 30 km under continents. Where is it thickest, by Kira's reading?

   • Under big mountain ranges, up to about 100 km
   • Under flat farmland
   • Under the oceans, since water adds weight
   • The same everywhere, about 30 km

5. Read this first

   Use this

   Cross-section, not to scale:

6. 5.

   Luz reads that the crust under the open Pacific Ocean floor, far from any island, is only about 5 km thick. What does that show?

   • The crust is the thickest layer anyway
   • Ocean crust is thicker than the crust under continents
   • Ocean crust is much thinner than continental crust
   • The Pacific floor sits right on top of the core
7. 6.

   Earth's plates are made of the crust plus the stiff top of the mantle. What is that rigid layer called, in Milo's notes?

   • The outer core
   • The asthenosphere
   • The inner core
   • The lithosphere
8. 7.

   Drawing of a boiled egg cut in half beside a cutaway of the Earth, not to scale. USGS says the core is unlike an egg yolk in one way. Which difference does Pia find?

   • The core is the thinnest layer
   • The core is made of stone, just like the mantle is
   • The core is cooler than the mantle
   • The core has two parts, one liquid and one solid
9. 8.

   In the egg model, the egg white stands for the mantle. In which way is the white a good match, says Ren?

   • It is runny and liquid, the way a lava ocean would be
   • It is a thick layer between the shell and the yolk
   • It is the thinnest part
   • It is the hottest part
11. 9.

    Tala makes a ball model of Earth about 13 cm wide, so 1 cm stands for about 1,000 km. About how thick is the 30 km continental crust on it?

    • About 30 cm
    • About 3 mm
    • About 3 cm
    • About 0.3 mm
12. 10.

    The deepest hole ever drilled is about 12 km (USGS). On the ball model, where 1 cm stands for about 1,000 km, how deep does Ari draw it?

    Use the picture in question 9.

    • About 12 cm, nearly across the whole ball
    • About 1.2 cm, well into the mantle
    • About 0.12 mm, not even through the crust
    • Down to the core