Question

The core of the Earth is made up of mainly
A. lead
B. mercury
C. iron
D. all the above

Answer 1

Hint: We know that the innermost layer of our planet is the core. Though metals are known to be the major composition of this layer, our planet also has other elements in smaller amounts. We have a clear idea that the core is further divided into inner and outer core. But remember, the major composition of both remains the same alloy.

Complete answer:
As we know, Earth comprises mainly four distinct layers. Innermost layer is the inner core, then we have the outer core, then comes the mantle and the outermost is the crust.

How deep is the core? Earth’s core is known to be very hot as well as a very dense centre of our planet found about 2900kms below the surface of the earth.
Let us now discuss its composition. Unlike the crust and mantle which are known to be mineral-rich, the core is mainly made up of metals- iron and nickel. Apart from these, there are siderophiles, the elements that dissolve in iron that is found in the core. Even though the major composition of the core is iron-nickel alloys, it isn’t heavier due to the abundance of sulfur.

Now let us discuss the composition of outer core and inner core separately.

Outer core: It is mostly composed of liquid iron and nickel, also these liquid metals has very low viscosity. Churning of these liquid metals in the outer core is the cause that creates as well as sustains Earth’s magnetic field.
Inner core: Again, iron is the major composition of this layer. But the state of this layer is plasma state due to intense pressure.

So, if we were to directly answer the question from the given options, we could say that the core of Earth is made up of mainly iron.

So, the correct answer is “Option C”.

Note:
You may be confused at the very first glance of the question because the question doesn’t specify as to which core is referred to here. But, the core, irrespective of whether it’s inner or outer, is mainly composed of metals- specifically iron and nickel.