Light travels quicker than sound. This phenomenon can be found in lightning too. You see the lightning then hear the thunder. :)
Answer:
C. The greater an element's density, the smaller the amount of it found in the crust
Explanation:
The layering of the Earth happened because of the different densities of the elements from which it was made. The denser elements started to sink deeper, the elements with medium density occupied the central part, and the elements with the smallest density remained at the surface. This resulted in the formation of the three basic layers of the Earth, core, mantle and crust. The core is composed of the densest elements, the mantle of the ones with medium density, and the crust from the ones with smallest density.
