What term refers to the surface and outermost layer of the Earth?

What term refers to the surface and outermost layer of the Earth?

• A. Crust
• B. Crystal
• C. Crystal planes
• D. Crystalline

Answer: (A)

The surface and outermost layer of the Earth is called the crust. This geological shell sits atop the mantle and includes two main types: continental crust, which is thicker and less dense, and oceanic crust, which is thinner and more dense. The crust forms the part of the planet you can stand on and study directly, and it makes up the outer layer of the lithosphere. The other terms relate to crystals in mineralogy: a crystal is any solid with a highly ordered internal structure; crystal planes are the flat faces within a crystal; and crystalline is an adjective describing something with a crystal-like structure. Because those terms describe microscopic or material properties of crystals, they don’t refer to Earth’s planetary layers.

The surface and outermost layer of the Earth is called the crust. This geological shell sits atop the mantle and includes two main types: continental crust, which is thicker and less dense, and oceanic crust, which is thinner and more dense. The crust forms the part of the planet you can stand on and study directly, and it makes up the outer layer of the lithosphere. The other terms relate to crystals in mineralogy: a crystal is any solid with a highly ordered internal structure; crystal planes are the flat faces within a crystal; and crystalline is an adjective describing something with a crystal-like structure. Because those terms describe microscopic or material properties of crystals, they don’t refer to Earth’s planetary layers.