The outermost part of the Earth is known as ________.
- AOption (a)
volcano
- BOption (b)
the crust
- COption (c)
the core
- DOption (d)
the mantle
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Correct answer
the crust
Why this answer is correct
The correct answer is the crust.
Key Points
- The crust is the outermost layer of the Earth, varying in thickness from about 5 km under the oceans to about 70 km under the continents.
- The crust is made up of a variety of rocks, primarily granite and basalt.
- It forms the solid surface of the Earth, where we live, and is divided into several tectonic plates.
- The Earth's crust is distinct from the underlying mantle and core, which are composed of different materials and have different physical properties.
Additional Information
- Volcano
- A volcano is an opening in the Earth's crust through which molten lava, ash, and gases are ejected.
- Volcanic activity is a result of the movement of tectonic plates and the presence of magma beneath the Earth's surface.
- Volcanoes can form on land or underwater, and they can create mountains and islands over time.
- The Core
- The core is the innermost part of the Earth, composed mainly of iron and nickel.
- It is divided into two parts: the solid inner core and the liquid outer core.
- The movement of the liquid outer core generates the Earth's magnetic field.
- The Mantle
- The mantle is the layer of the Earth located between the crust and the core.
- It is composed of silicate rocks that are rich in iron and magnesium.
- The mantle extends to a depth of about 2,900 kilometers (1,800 miles) and is involved in tectonic activity and convection currents.