What is the correct sequence of layers of Earth from the outside of the planet to the inside? 

The correct answer is Crust (outermost) - mantle - core (innermost)

Key Points

• The Earth can be divided into several layers from the outermost to the innermost based on their compositional and physical properties. 
• The correct sequence is Crust (outermost) - mantle - core (innermost).
  • Crust:
    • This is the Earth's outermost layer, and it's where we live.
    • It's the thinnest layer, varying from about 5 kilometers in thickness in the oceanic crust to about 30-70 kilometers in the continental crust. The crust is largely composed of lighter rocks, such as granite and basalt.
  • Mantle:
    • Beneath the crust, the mantle extends up to 2900 kilometers into Earth.
    • It is composed primarily of silicate rocks that are richer in iron and magnesium than the crust.
    • The mantle can be divided further into the upper and lower mantle. The asthenosphere, a part of the upper mantle, behaves plastically due to the intense heat and pressure.
  • Outer Core:
    • The outer core, lying beneath the mantle, is mostly composed of liquid iron and nickel.
    • This liquid layer is about 2200 kilometers thick and creates Earth's magnetic field due to its liquid state and its circulation movement.
  • Inner Core:
    • The innermost layer, the inner core, is a solid ball consisting primarily of iron and nickel.
    • Despite the extremely high temperature, the enormous pressure at this depth keeps the material solid.
    • The radius is around 1250 kilometers.
  • Between each of these main layers, there are also transitional zones known as the lithosphere (between the crust and the mantle), the Gutenberg discontinuity (between the mantle and the outer core), and the Lehmann discontinuity (between the outer core and the inner core).