Hot magma when reaches on earth's surface is known as:
The correct answer is Lava.
Explanation:
When hot magma, which is molten rock beneath the Earth's surface, reaches the Earth's surface, it is known as lava. Lava is typically associated with volcanic eruptions and is expelled from a volcano or volcanic vent.
Here are some key points to understand about lava:
1. Lava Composition: Lava is primarily composed of molten rock, gases, and other materials such as minerals and crystals.
2. Types of Lava: Lava can have different compositions, resulting in different types. The two main types of lava are:
- Basaltic Lava: This type of lava is low in silica content and has a relatively low viscosity, allowing it to flow easily. It often forms extensive lava flows and is commonly found in shield volcanoes.
- Rhyolitic Lava: This type of lava is high in silica content and has a high viscosity, making it more sticky and slow-moving. It tends to form domes and short, stubby lava flows.
3. Lava Characteristics: Lava can range in temperature from around 700 to 1,200 degrees Celsius. It can flow slowly or rapidly depending on its viscosity and slope of the terrain. The color of lava can vary depending on the minerals present, ranging from black to red or even blue in some cases.
4. Effects of Lava: Lava flows can cause significant damage to surrounding areas, including destruction of vegetation, infrastructure, and homes. However, lava flows also contribute to the formation of new land and can create fertile soil over time.
In conclusion, when hot magma reaches the Earth's surface, it is known as lava. Lava is a molten rock that can flow from volcanoes or volcanic vents during eruptions. Understanding the characteristics and types of lava is important in studying volcanic activity and its impact on the Earth's surface.

C lava