Video Transcript
What is the chemical composition of
the outer core? (A) Iron, magnesium, and silicon
oxides, (B) silica and aluminum, (C) silica and magnesium, (D) molten iron and
nickel, (E) molten iron only.
To answer this question, we need to
recall the chemical composition of the outer core of Earth. The outer core is one of the four
main layers of the Earth. Each layer has a different
composition and properties. The crust is the thinnest
layer. Continental crust is composed of
rocks rich in silica and aluminum, and oceanic crust is composed of rocks rich in
silica and magnesium. The mantle lies directly beneath
the crust and is the thickest layer of Earth’s internal structure. The mantle is primarily composed of
iron, magnesium, and silicon oxides.
Below the mantle is the core. The core is very hot and very
dense. Both the outer core and the inner
core are composed of iron and nickel. Due to the very high temperatures,
the outer core is a layer of molten iron and nickel. But due to the extremely high
pressures at the center of the Earth, the inner core is solid iron and nickel. We now know that the chemical
composition of the outer core is molten iron and nickel.
