Fresh and salt water

the process in which farmland becomes less productive because the land is degraded

a layer of gases

evaporation, condensation, precipitation, runoff

forest, savanna, grasslands, and desert

Continental and Oceanic

an increase in the average temperature of the Earth's atmosphere

solid iron and nickel

the heat of the sun causes water on the Earth to go into the air

the revolution around the sun and the Earth's tilt cause the seasons

inner core, outer core, mantle, crust, and atmosphere

the typical weather conditions of a region over a long period of time

soft layer of hot rock

the water soaks into the ground, or runs off into the river

hills, mountains, plateaus, and plains

tectonic plates movements
earthquakes
volcanoes

supercontinent Pangaea broke into pieces that drifted apart

mostly made up of liquid metals

the water vapor cools and condenses into droplets of water that form clouds

rivers and lakes

mechanical weathering
chemical weathering
erosion

The earth's crust divided into a number of large rigid pieces

Earth's thin outer layer

when droplets become too heavy for the air to hold them

weathering and erosion