Question

The layer just below the crust is called the _____.
A. Sial
B. Sima
C. Mantle
D. Core

Answer 1

Hint: The Earth’s crust is the thin shell on the outside of Earth and it accounts for 1% of the Earth’s volume. It is the top component of the Lithosphere. The Earth’s crust in the oceans is usually 5 to 10 km thick whereas in the continents it is 30 to 50 km thick.

Complete answer: - Option A: Sial is the uppermost layer of the Earth’s crust and is made up of Silicate (Si) and Aluminium (Al) from which it gets its name. These elements are less dense than the majority of the elements in the Earth, thus form the topmost layer. Sial is mostly absent from the Ocean layers. Hence, this is an incorrect option.
- Option B: Sima is the lower layer of the Earth’s crust and is made up of Silicate (Si) and Magnesia (Ma) from which it gets its name. Ocean layers are mainly of Sima. Hence, this is an incorrect option.
- Option C: Mantle is the layer below the Earth’s crust and above the core of the Earth. The forms a solid layer of silicate rock between the crust and the core. It is mostly solid but as it goes deeper the form starts changing. Hence, this is the correct option.
- Option D: Core is the innermost layer of the planet and can be entirely liquid or solid. Earth’s core is a mix of liquid and solid. It is made up of entirely iron and nickel which makes it so hot. Hence, this is an incorrect option.

Therefore the correct answer is option (C)

Note: The Earth’s crust is made up of less dense materials as they rise above the other elements that are present inside the Earth. The other layers are made of more dense materials so they lie below.