Transcript Chapter 6
Chapter 6 Resources and Our Environment BFRB Pages 205 - 208 Renewable Resources Renewable Resource Def. - a resource that can be replaced in nature at a rate close to its rate of use by humans. – Examples – water, oxygen, trees, food, solar energy. Nonrenewable Resources Nonrenewable Resource - Def. – resource that exists in a fixed amount or is used up faster than it can be replaced in nature. – – – – Examples: Metals - gold, silver, iron, copper, aluminum. Non-metals - sand, gravel, limestone, sulfur. Energy – coal, oil, natural gas, uranium. Some geological resources can be reused through recycling (aluminum, copper), but most are destroyed through use (oil, coal, natural gas) How are Renewable Resources Renewed? Air – Respiration and Photosynthesis renew Oxygen and CO2 The Water Cycle renews water Humans can plant new trees and crops when we use them. Pollution Def. - Occurs when some part of the environment is changed in a way that makes it unfit for human, plant, or animal use. Air Pollution – Example 1 – Acid Rain – Is created when sulfur dioxide (a gas that is created when oil and coal are burned) combines with water droplets in the air. – Example 2 – Greenhouse effect – Hydrocarbon particles enter the air through the burning of fossil fuels. They trap the heat in the atmosphere raising the temperature. Water Pollution Humans give off industrial waste and domestic waste. Pesticides, sewage, oil leaks and spills contaminate our water supply. Surface and groundwater supplies become polluted. Groundwater is especially harmed because the water cycle can’t help clean ground water quickly. (no evaporation…) Nonrenewable Resources #1 Minerals and Ores – – A valuable mineral (gold, iron, silver, etc.) is called an ore mineral. – The low value (common) mineral that is found with the ore is called gangue (gang). – Reserves is the known amount of ore that is left in the ground that can still be mined. Nonrenewable Resources cont’d #2 Fossil Fuels – Def. – fuels that form from the remains of plants and animals that lived long ago. – Ex – coal, oil, natural gas. Burning fossil fuels releases the energy that is stored in them. Nonrenewable Resources cont’d #3 Uranium – used in nuclear reactors to generate electricity. At the present rate of use, U.S. uranium stores will last another 30 years. FYI – A Uranium atom is hit with a neutron and split (nuclear fission). This process releases different elements, a few neutrons, and a tremendous amount of energy (heat) This heat is used to heat water, create steam, which turns a turbine to create electrical energy How do we make our natural resources last longer? Energy Conservation – – Use less energy Recycling And most importantly….. Find Alternative Energy Resources to the top four right energy sources now: Oil Natural gas Coal Nuclear Alternative Energy Resources Water – Hydroelectric – Dams let water run through them to run turbines which create electricity. Wind Power – Windmills – Windmill farms – the fans create electricity Solar Energy – Solar Cells – Limitless resource Geothermal Energy – Heat from within Earth – Steam or Hot water from Earth can run turbines or heat homes – Used in Geysers in California/ Iceland Problems that we create by using natural resources… Acid Rain Global Warming Toxic wastes – by-products of industrial processes. Nuclear Power – Waste Disposal – by-products remain radioactive for many years. – Nuclear Power Plant Accidents. Recycling – Necessary, but expensive