Question

Given below are 4 statements (A), (B), (C) and (D). Please read them carefully and response the question given after these statements.
(A) The crust of the earth comprises of rocks rich in Silica and Aluminium.
(B) The core of the earth consists of metals in liquid state of high temperature and pressure.
(C) The Magnesium and Phosphorus are dominant in the core of the earth.
(D) Hydrosphere covers approximately 71% of the total surface area of the earth.
Choose the correct answer from the options given below :

• A. (A) and (B) only are correct statements.
• B. (A) and (D) only are correct statements.
• C. (B), (C) and (D) only are correct statements.
• D. (A), (B) and (D) only are correct statements.

Hint:

Acronyms to remember: \textbf{SIAL} (Crust: Silica + Al), \textbf{SIMA} (Lower Crust/Mantle: Silica + Mg), \textbf{NIFE} (Core: Ni + Fe).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This question tests knowledge of the internal structure of the Earth (Crust, Mantle, Core) and the Earth's surface composition.
Step 2: Detailed Explanation:
1. Statement (A): Correct. The continental crust is primarily made of SIAL (Silica and Aluminium).
2. Statement (B): Correct. While the inner core is solid due to immense pressure, the outer core is in a liquid/molten state consisting of Iron and Nickel at extremely high temperatures. Generally, the statement regarding the core containing liquid metals is accepted as true in this context.
3. Statement (C): Incorrect. The core is dominant in Iron and Nickel (called NIFE). Magnesium is more abundant in the mantle and the lower crust (SIMA). Phosphorus is not a dominant metal in the core.
4. Statement (D): Correct. Water (Hydrosphere) covers about 71% of the Earth's surface.
Step 3: Final Answer:
Statements (A), (B), and (D) are correct.