Unit 2

Question 1

How are igneous rocks formed?

Answer 1

Igneous rocks are formed from the solidification of molten rock (a melt).

Question 2

What is the difference between lava and magma?

Answer 2

Magma is molten rock stored beneath Earth’s crust. Lava is magma that reaches the surface through a volcano vent.

Question 3

Where is the extrusive realm? Where do extrusive igneous rocks cool?

Answer 3

Above ground.

Question 3

Where is the intrusive realm? Where do intrusive igneous rocks cool?

Answer 3

Below ground.

Question 4

What is molten rock referred to as?

Answer 4

A melt.

Question 5

The crust and asthenosphere are mostly ______.

Answer 5

solid rock

Question 6

The mantle is ______ km thick, surrounds _____ and is almost all _____. A small percentage is _____ in the _______.

Answer 6

2800, Earth’s core, solid, molten, transition zone

Question 7

What are the three reasons solid rock in the transition zone melts?

Answer 7

Decrease in pressure, introduction of volatiles, heat transfer