Chemical composition and mechanical properties of. Based on composition Earth is made up of the rocky crust the mantle made of rock-forming materials and the metallic iron-nickel core. The Earth S Structure Weather processes occur in. . The solid crust is the outermost and thinnest layer of our planet. The crust averages 25 miles 40 kilometers in. Earths layers are. The composition and viscosity of minerals. Believe the correct answer from the choices listed above is option A. Chemical composition and thickness of layers b. Chemical composition and thickness of layers b. Troposphere Stratosphere Mesosphere and Thermosphere and they are separated based on temperature. The most common method for the inside of the Earth is based on chemical composition and splits it up into a crust mantle outer core and inner core. The two principal ways to describe Earths structure are based on the _____. Sc...