Earth's Systems

The earth is composed mainly of

• water

• rock

• metal

• air

________ of the earth’s surface is covered by water:

• 100%

• 90%

• 75%

• 60%

Earth’s inner core is composed mainly of:

• molten rock

• liquid iron and nickel

• heated gases

• solid iron and nickel

Earth’s inner core is surrounding by:

• liquid iron and nickel

• solid nickel and copper

• heated gases

Earth’s outer layer is called the ________ :

• inner core

• outer core

• mantle

• crust

Tectonic plates:

(select all that apply)

• always move very slowly

• sometimes press against or pull away from each

• sometimes scrape against each other

• can move quickly

Mountains form where tectonic plates diverge on continents.

• True

• False

Volcanic activity is related to tectonic plate movement:

• True

• False

Seismologists study:

• Ocean tides

• Mountainside erosion

• Volcanic activity

• Earthquakes

Which crust is the thickest but least dense?

• Continental

• Oceanic