Extrusión

The video explains how magma cools to form rocks, highlighting that magma cools faster above ground, resulting in smaller mineral grains. It also discusses basalt as the most common type of extrusive rock.

What are the two types of magma flows mentioned in the video?

• Constant flows and violent eruptions

• Slow flows and rapid eruptions

• Gentle flows and explosive eruptions

• Steady flows and mild eruptions

Why do rocks formed from magma above ground have smaller mineral grains?

• Because they are formed under pressure

• Because they are mixed with water

• Because they cool faster than underground

• Because they are exposed to sunlight

What is the primary reason for the absence of large crystals in extrusive rocks?

• Rapid cooling

• High pressure

• Lack of minerals

• Low temperature

Which type of rock is most commonly formed from extrusive processes?

• Granite

• Basalt

• Marble

• Slate

What characteristic is typical of mineral grains in extrusive rocks?

• They are large and well-formed

• They are small and fine

• They are irregular and rough

• They are smooth and shiny