This chapter reviews light and sound waves, including how they are sensed by people. Earth Sciences - Rocks and Soil Rocks are made of one or more kinds of minerals. The three kinds of rocks are igneous, sedimentary, and metamorphic. Soil is formed when rock is broken into small particles. This chapter reviews the formation and types of rocks and soil.
People mostly observe changes in the crust.
The rocks are weathered to create soil and the soil is carried from place to place by erosion. Changes in the earth's crust can also come from inside the earth when there are earthquakes or volcanoes. This chapter reviews the parts of the earth and how the earth changes. Earth Sciences - Weather Weather is the condition of the air around us. Precipitation is an important part of weather.