The earth's envelope comprises the lithosphere (consisting of the earth's crust and the uppermost mantle ) down to a depth of 16 km, the hydrosphere (flowing and standing water ), the atmosphere ( air envelope ) and the earth's biosphere ( fauna and flora ) .
The earth's shell is made up of more than 90 chemical elements and / or their compounds , eight of which have a mass fraction of more than 1 percent each and together make up around 98 percent by mass of the earth's shell. Of these eight elements, oxygen with 49 percent and silicon with 26 percent are the two most common elements, followed by aluminum (7.6%), iron (4.7%), calcium (3.4%), sodium (2.6 %), Potassium (2.4%) and magnesium (1.9%).
The rarest elements on earth include the very rare intermediate products of radioactive decay series such as astatine ( 3rde-21 ppmw ), the rarest element in the earth's envelope, thenoble gas xenon(9the-6 ppmw) andkrypton(1.9e-5 ppmw) andrhodium(0.001 ppmw), the rarestmetal inthe earth's shell.
- Frequencies on earth in the list of abundances of chemical elements
- Landscape sphere
- Environmental compartment