Question

1. which of the following would not describe the formation of an igneous rock with a glassy texture?

• it is formed at the surface of earth.
• it is formed as an intrusive rock.
• it is formed from extremely thick magma that cools quickly.
• it may have formed when lava hit water.

Explanation:

Glassy igneous rocks (like obsidian) form from rapid cooling of lava/magma, often at Earth's surface (extrusive) or when lava hits water. Intrusive rocks form deep underground, cooling slowly which allows crystal growth, preventing a glassy texture. So describing it as an intrusive rock does not fit the formation of a glassy igneous rock.

Answer:

It is formed as an intrusive rock.