The Earth

The Earth’s Properties, Structure, and Composition
211.   The Planet Earth
212.   The Earth’s Physical Properties
213.   The Structure and Composition of the Earth’s Interior
214.   The Earth’s Constituent Minerals and Rocks

The Earth’s Envelope: Its Atmosphere and Hydrosphere
221.   The Atmosphere
222.   The Hydrosphere: the Oceans, Freshwater Bodies, and Ice Masses
223.   Weather and Climate

The Earth’s Surface Features
231.   Physical Features of the Earth’s Surface
232.   Features Produced by Geomorphic Processes Acting on the Earth’s Surface

The Earth’s History
241.   Origin and Development of the Earth and Its Envelopes
242.   The Interpretation of the Geological Record
243.   The Eras and Periods of Geological Time