Igneous Rocks

Igneous rocks are made up of elements like ________.

• silicon

• aluminum

• iron

• all of the above

If a rock contains many crystals, its texture will be ________.

• smooth

• coarse

• soft

• hard

Magma that cools slowly below the earth’s surface forms ________.

• lava

• intrusive rocks

• extrusive rocks

• all of the above

Magma reaches the earth’s surface through ________.

• volcanoes

• mid-ocean ridges

• cracks in the ocean floor

• all of the above

The lava that forms extrusive igneous rocks cools quickly so ________ crystals form.

• large

• many

• few to no

• small

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