The crust is the Earth's outermost layer that is less than           percent of Earth by mass, with oceanic crust and continental crust often consisting of more felsic rocks.

Correct Answer 1

Key Points:Crust:

• The uppermost layer over the earth’s surface is called the crust.
• It is the thinnest of all the layers.
• On the continental masses, It is about 35 km and on the ocean floors, only 5 km.
• The density of the rocks found at the surface rocks: 2.7 - 2.9 gm/cm3
• The density of rocks found at the sea floor is around: 3.0 gm/cm3
• The oceanic crust is denser than the continental crust.
• The Earth’s crust is the thinnest layer and makes up less than 1% of the Earth’s volume and about 0.5% of the Earth’s mass.
• The earth is made up of several concentric layers with one inside another, just like an onion.
• The crust is the outermost layer of Earth and is made up of igneous, metamorphic, and sedimentary rocks. 
• The Earth's crust is unstable because of the exogenic forces.

Discontinuity:

• All those layers are separated from each other through a transition zone.
• These transition zones are called discontinuities.
• Conrad Discontinuity: It lies between the Upper crust and Lower crust.
• Mohorovicic Discontinuity: It lies between crust and mantle.
• Repiti Discontinuity: It lies between the Upper mantle and Lower mantle.
• Gutenberg Discontinuity: It lies between core and mantle.
• Lehman Discontinuity: It lies between the upper core and lower core.​
• Discontinuities are the transition zones that separated the layers of the earth. 
• Earth’s interior is made of different kinds of materials.
• Each of those materials is different from the others by their physical and chemical properties, such as temperature, density, etc.