Environmental Science Chapter 23 Practice

Your Results for "Practice Quiz" Study Area for Withgott, Environment: The Science Behind the Stories, 5/e Minerals and Mining > Practice 1. Efforts have been made in the last 10 years to change the General Mining Act of 1872. Supporters of the act argue that it should not be changed because __________. Your Answer: mining companies take large financial risks in opening a mine so they should be entitled to the large financial rewards if the mine is successful. They also argue that the lack of royalty payments is needed to keep the U.S. mining industry going. 2. Which of these is NOT an effect of the increased use of mountaintop removal mining in the Appalachian Mountains? Your Answer: increasing employment opportunities as more workers are needed Because of the efficiency of mountaintop removal, fewer workers are needed and unemployment has risen. 3. In order for mining of minerals to be sustainable, we will need to __________. Your Answer: consider that minerals are a nonrenewable resource, so mining them cannot be sustainable While we can make better use of the minerals we mine, the finite supply of minerals makes them nonrenewable. 4. What materials are mined using placer mining? Your Answer: precious metals and gems This is the technique used by the Congo’s coltan miners to find tantalite. 5. Which of these materials is NOT currently mined from the ocean floor? Your Answer: manganese nodules Even though there are trillions of tons of manganese nodules on the ocean floor, we do not yet have an economically viable method of mining it. 6. Which of these is FALSE concerning the laws that govern mining on public land in the United States? Your Answer: All mine contracts have required the mining company to restore the mined area to premining conditions once the mine is closed. No such requirement is in place. 7. Which of the following has undergone the most processing (has been through the most changes from when it was found in the ground)? Your Answer: alloy To make an alloy, a rock is processed to get out the metal, and then the metal is heated with another material to make the alloy. 8. Why have some open pit mines been declared Superfund sites? Your Answer: The waters in the pit become highly acidic and contain high levels of toxic metals. The toxic waters of the Berkeley Pit make it one of the largest Superfund sites in the country. 9. Salt deposits in Michigan occur in concentrated veins deep underground. What would be the best method for mining these salt deposits? Your Answer: subsurface mining Deep deposits are typically accessed through subsurface mining. 10. Acid drainage does not normally occur in areas before mines are built but tends to happen after the mine has been in operation for many years. What causes acid drainage? Your Answer: Mining exposes unweathered rock surfaces that react with water and the atmosphere to generate acids. The large amount of freshly exposed rock provides the sulfur to generate sulfuric acid. 11. Which of these is NOT a use for materials mined from Earth? Your Answer: All of the above come from mined materials. Mined materials are used in almost every aspect of our lives. 12. Reclamation (restoration) of mined areas to their pre-mined condition has been difficult in the United States because __________. Your Answer: fast-growing plants used in the early stages of reclamation to prevent erosion may impede the growth of other plant species that would be needed for a diverse ecosystem Ironically, by trying to do the right thing and prevent erosion, reclamation efforts may become more difficult. 13. Which type of mining causes large amounts of sediment and debris to choke rivers and streams as its main environmental impact? Your Answer: placer mining By using running water to flush away unwanted sediment, placer mining causes pollution of streams and rivers. 14. Mine tailings are __________. Your Answer: the remains of ore after most of the metals have been removed These mine wastes can contribute to water pollution. 15. The most dangerous form of mining (for the miners) is __________. Your Answer: subsurface mining In addition to the risk of explosions, miners are subject to air pollutants that can lead to respiratory diseases. 16. Strip mining, subsurface mining, and solution mining all take place in which "sphere" of the planet? Your Answer: lithosphere The upper region of Earth's crust is the lithosphere. 17. Each year 1.2 billion mobile phones are sold. What percent of old mobile phones are currently recycled? Your Answer: 10% Only 10% of cell phones are recycled. 18. Which of these is NOT a reason that we have difficulty making accurate estimates of how long our available reserves of minerals will last? Your Answer: We are unsure of the rate at which minerals are replaced in Earth's crust. We know that the minerals in Earth's crust are not replaced quickly enough to matter in our calculations. 19. One way to prolong our supply of minerals is through recycling. Recycling of minerals __________. Your Answer: also uses far less energy than production of minerals from ore Recycling uses far less energy than production from raw ore. For aluminum, making new aluminum uses 20 times more energy than recycling it. 20. Why do scientists think that the environment and human health cannot be restored to their original conditions after mountaintop mining? Your Answer: Groundwater remains polluted, even after reclamation efforts. A USGS (United Stated Geological Survey) study showed that, even after reclamation efforts, groundwater from wells near mining sites still had high levels of mine-derived chemicals. 21. While solution mining typically poses fewer environmental risks than other mining techniques, its main potential hazard is __________. Your Answer: contamination of groundwater with acids or heavy metals Because solution mining involves pumping acids or other liquids into the ground, some of the liquids could seep into groundwater carrying dissolved metals with them. 22. One of the steps in processing some metals is smelting. What does smelting do for a metal? Your Answer: Smelting allows us to alter the properties of a metal to suit particular needs. Smelting iron with carbon makes steel—a material that has better strength and malleability characteristics for many applications. 23. Based on the broad definition of "mining," harvesting of which of these materials would NOT be considered mining? Your Answer: freshly deposited sediments from a river estuary Because a river is constantly depositing sediments in its estuary, this would be a renewable resource and would not be considered mining. 24. Which type of mining generates "overburden"? Your Answer: strip mining The overburden is the top layers of earth removed to get at the mineral resources. It is replaced once the minerals have been removed. 25. Tantalum is needed for mobile phones, and the Congo was a major supplier of this metal. Which of these is true of how mining for tantalum has occurred in the Congo? Your Answer: Profits from tantalum mining have helped fuel a war that has killed more than 5 million people. Warring militias seized control of the mining operations and used the profits to fund their wars.