Chapter 9 Lessons 1, 2, and 3 By: Charlotte, Maggie, Mia, and Olivia
Lesson 1 Earths Crust The outer surface of Earth is called the crust. The crust covers all of the Earth. In places such as oceans, the crust is underwater.
Physical and Chemical Weathering In physical weathering, only the size of rocks is changed. In chemical weathering chemicals cause rocks to change into different materials.
Lesson 2 Gravity and Avalanches In colder areas, an avalanche is the name for a large amount of snow. Strong winds, earthquakes, and explosions trigger an avalanche. Landslides and avalanches can cause damage.
Erosion by Moving Water Water, ice, and gravity can work together to move weathered pieces of rock. The faster water moves the heaver pieces.
Lesson 3 How Volcano's Form A volcano is a landform that can bring about a rapid change to Earth’s surface. Before a volcano forms, things happen deep underground. A very hot rock, called magma is practiclly melted into liquid.