What is the outer core?

What is the outer core?

• A. A solid stone shell
• B. A gas layer
• C. A layer of ice
• D. Mass of molten iron surrounding the inner core

Answer: (D)

The outer core is a molten metal layer surrounding the solid inner core. It is mainly iron and nickel in a liquid state, kept molten by the extreme heat at the Earth's center. The flowing liquid iron generates Earth's magnetic field through convective motion, a process known as the geodynamo. So describing it as a mass of molten iron surrounding the inner core matches what the outer core is. The other ideas don’t fit: it isn’t a solid shell, a gas layer, or made of ice.

The outer core is a molten metal layer surrounding the solid inner core. It is mainly iron and nickel in a liquid state, kept molten by the extreme heat at the Earth's center. The flowing liquid iron generates Earth's magnetic field through convective motion, a process known as the geodynamo. So describing it as a mass of molten iron surrounding the inner core matches what the outer core is. The other ideas don’t fit: it isn’t a solid shell, a gas layer, or made of ice.