Chapter 2: Minerals & Rocks - Section 3: Igneous Rocks

Rocks that form when magma (heats, cools) and hardens are called igneous rocks.

• heats

• cools

The texture of an igneous rock is determined by the number of (cracks, crystals) the rock contains.

• cracks

• crystals

Intrusive rocks form when magma cools (quickly, slowly) below the earth’s surface.

• quickly

• slowly

Magma that reaches the earth’s surface becomes (lava, gas).

• lava

• gas

Extrusive rocks form when magma reaches the earth’s surface, becomes lava, and cools (quickly, slowly).

• quickly

• slowly

Use page 20 of the student text to complete the worksheet. True/False. Decide if each statement is true or false, and write true or false in the blank. Igneous rocks can form above or below the earth’s surface.

• True

• False

• Only above the earth's surface

• Only below the earth's surface

The only type of igneous rock is extrusive rock. True or False.

• False

• True

• Intrusive rock

• Metamorphic rock

If a rock contains many crystals, its texture will be glass-like. True or False.

• False

• True

• Maybe

• Not sure

Magma that is trapped and insulated cools slowly. True or False.

• True

• False

• Quickly

• Not at all

Magma reaches the earth’s surface through volcanoes, mid-ocean ridges, and cracks in the ocean floor. True or False.

• True

• False

• Only through volcanoes

• Only through mid-ocean ridges