Earth and Space — Planet Earth

Plate tectonics and the atmosphereSign up

Describe the model of plate tectonics, in which a solid outer layer (made up of the crust and uppermost mantle) moves because of flow lower in the mantle. · Describe how earthquakes, volcanoes and fold mountains occur near the boundaries of tectonic plates. · Know that clean, dry air contains 78% nitrogen, 21% oxygen and small amounts of carbon dioxide and other gases, and this composition can change because of pollution and natural emissions.