Igneous Rocks

Multiple Choice

Which of the following best describes a rock?

• A naturally formed solid made up of one or more kinds of minerals.

• A liquid substance found underground.

• A man-made object used in construction.

• A gas released during volcanic eruptions.

Multiple Choice

Which type of rock forms from molten rock called magma found below the Earth's surface?

• Sedimentary rock

• Metamorphic rock

• Igneous rock

• Limestone

Open Ended

Explain how the classification of igneous rocks depends on both mineral composition and crystal size.

Multiple Select

Which characteristics are true for intrusive igneous rocks?

• Form below Earth's surface

• Have large crystals

• Form from lava

• Cool quickly

Fill in the Blank

Fill in the blank: Lava forming extrusive, igneous rock reaches Earth's surface and forms ___ crystals due to quick cooling time.

Open Ended

Describe how some igneous rocks can contain crystals of different sizes and what this indicates about their formation.

Open Ended

Describe how some igneous rocks can contain crystals of different sizes and what this indicates about their formation.

Fill in the Blank

Most igneous rocks are made up of silicate minerals commonly found in Earth's ___.

Multiple Choice

Compare and contrast the characteristics of intrusive and extrusive igneous rocks as described in the slides.

• Intrusive rocks have high heat, large crystals, and form inside Earth, while extrusive rocks have low heat, small crystals, and form outside Earth.

• Intrusive rocks have low heat, small crystals, and form outside Earth, while extrusive rocks have high heat, large crystals, and form inside Earth.

• Both intrusive and extrusive rocks have high heat and large crystals.

• Both intrusive and extrusive rocks form inside Earth and have small crystals.

Fill in the Blank

A ___ is a naturally formed solid made up of one or more kinds of minerals.

Open Ended

Why do igneous rocks form at Earth's surface and are different from those formed within Earth? Why is silica content important in classifying igneous rocks?