2 Formation of Earth The Nebular Hypothesis bodies in our solar system evolved from an enormous rotating cloud called the solar nebula.mostly hydrogen and helium, with some heavier elements.
3 DifferentiationAs Earth cooled, layers formed through a process called differentiation.Denser elements (iron and nickel) sunk to Earth’s core.Lighter material migrated outward forming the mantle and crust.
4 Earth’s Four Spheres Solid Earth (Lithosphere) Hydrosphere Atmosphere Biosphere
5 Solid Earth Core mostly iron and nickel densest part of Earth inner core solidMantlemostly iron andmagnesiumliquidCrustmostly silicon andoxygenrigid outer layer
6 Earth’s Crust The earth’s crust is divided into: Continental crust Oceanic crust
7 Hydrosphere Ocean (the most prominent feature of the hydrosphere) a. Nearly 71% of Earth’s surfaceb. About 97% of the earth’s waterFresh watera. glaciersb. rivers and lakesc. groundwater
8 Atmosphere Gaseous envelope surrounding Earth a. life-giving gases b. protects organisms from intense heat and radiation from the sun
9 BiosphereIncludes all lifeInfluences the other three spheres