Correct Answer: Option C) 1 & 3
Statement 1: The core-mantle boundary lies at around 2900 km depth.This statement is correct. The core-mantle boundary, also known as the Gutenberg discontinuity, is located at approximately 2,900 kilometers below Earth's surface. This boundary separates the silicate mantle from the metallic core.
Statement 2: Pressure decreases with increasing depth.This statement is Incorrect. Pressure actually INCREASES with increasing depth due to the weight of overlying rock layers. As you go deeper into the Earth, the pressure becomes progressively greater because of the gravitational compression from all the material above.
Statement 3: The inner core has a density of about 13 g/cm³.This statement is correct. The inner core, composed primarily of iron and nickel under extreme pressure and temperature conditions, has a density of approximately 13 grams per cubic centimeter. This high density is due to the metallic composition and the intense pressure at Earth's center.
