Igneous

The video explains igneous rocks, the most common rock type on Earth, and their formation. It distinguishes between extrusive igneous rocks, formed when lava cools on the surface, and intrusive igneous rocks, which form underground.

What are the three types of rocks mentioned in the text?

What is the composition of the Earth's crust in terms of rock types?

What percentage of the Earth's crust is made up of sedimentary and metamorphic rocks?

How are extrusive igneous rocks formed?

What distinguishes intrusive igneous rocks from extrusive igneous rocks?