Physical and Chemical Weathering

See Think Wonder Watch the Video then write down what do you see, think and wonder about the video What did you see think wonder about the video? Weathering is the physical or chemical breakdown of rock into smaller particles. There are 2 types of weathering physical and chemical.Physical weathering, also known as mechanical weathering is when a physical process naturally breaks rock into smaller pieces. The chemical makeup is NOT changed Physical Weathering changes the chemical makeup of a rock. True False A common example is ice wedging. Ice wedging occurs when water seeps into a crack of a rock and freezes. As it freezes the water expands. After several cycles the rock will split in half. Root wedgingTrees and plants can grow roots through the crack of rocks and cause them to break over time AbrasionThe process when sedimentscarried by streams or wind grindagainst other rocks ExfoliationExtreme temperature changes (heat) causes rock to expand Animals o Small animals burrowing under ground creating tunnels Chemical Weathering Chemical weathering is when the materials that are apart of a rock change into new materials. The chemical makeup is changed. The substance is different from before. Acid rain Burning of fossil fuels causes the precipitation to become acidic. The acid rain causes certain materials such as limestone to dissolve Oxidation When the rocks or minerals chemically react with oxygen such as iron turning into rust Weatheringanderosionare natural processes that shape and reshape Earth’s surface. They usually happen very slowly, so you may not see changes from day to day. But over time, they can lead to the formation of new islands, carve out canyons and wear down mountains. Weathering and erosion are why coastlines look the way they do. Their patterns can help us predict what land will look like in the future. For example, the coast of Cape Cod in Massachusetts has more islands now than it did in 1984. Some of its beaches lose over a foot of shoreline every year.Which of these best describes weathering and erosion? They are tools people use to change landforms and create new ones. They only affect one landform: islands. They cause tiny changes to Earth’s surface that become enormous over time. They significantly change the surface of the Earth every few days. Chemical weathering occurs when the composition of a rock changes due to a chemical reaction. Chemical weathering can be caused by exposure to natural materials like carbon dioxide, oxygen and water. It is also caused by acid rain. Pollution is a major factor leading to acid rain. When smoke from factories and other sources is released into the air, it increases levels of greenhouse gases in Earth’s atmosphere. The greenhouse gases increase the acidity of the water in clouds, which then release acid rain. Acid rain kills plants, fish and other aquatic animals. It also speeds the weathering of rocks, especially limestone—a type of rock commonly used in building construction.Which of these best describes the relationship between smoke from factories and acid rain? Smoke travels directly into clouds, creating acid rain. Smoke turns clouds black, which causes them to become more acidic and release black acid rain. Smoke increases greenhouse gases, which make the water in clouds more acidic so they release acid rain. Smoke wipes out all the greenhouse gases in the atmosphere, increasing the acidity of clouds so they create acid rain.