What are the 3 main layers of the earth and what do they consist of

The 3 main layers are the crust, the mantle, and the core. The crust consists of everything you see- dirt, rock, minerals, and everything you can see. We live on the crust, and it floats around on the magma in pieces we call continents. The next layer is the mantle, which is where all the magma is- this is what the crust floats on. It consists of molten rock and minerals; the bottom layer of the crust is continually melting under the extreme heat, but it is replaced when volcanoes spew the magma back onto the surface. The last layer is the core, an extremely fast-spinning ball of heavy metals. It is split into two layers; inner and outer core. The outer core is mostly an alloy of nickel and iron with some other heavy metals thrown in, like platinum and gold, but the inner core is almost solid iron. It is so hot that it should be melted, but the pressure of everything on top of it makes it so it has nowhere to melt to, keeping it solid.
Hope this helps!!! ^_^

The correct answer is b