8928809
Descrição
FlashCards por Shreya Manna, atualizado more than 1 year ago
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Criado por Shreya Manna
mais de 7 anos atrás
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| Questão | Responda |
| How many elements are there in the periodic table? | About 100 elements |
| What layers make up the Earth? | |
| Which parts of the earth are cracked into a number of large pieces (tectonic plates)? | The upper mantle and crust |
| Why do the tectonic plates move? What speed do they move at every year? | -Convection currents in earth's mantle - Because of heat released by natural radioactive processes - Cause plates to move at relative speeds of a few cm every year |
| Describe the nature of the mantle | Mostly solid but can move slowly |
| What has extra carbon dioxide done to the environment (e.g. oceans)? | Oceans are reservoir for CO2 Increased amount of carbon dioxide absorbed by oceans has an impact on marine environment - more carbonate rocks formed - coral reefs dying - acidic conditions due to excess CO2 |
| What happens to the carbon in the air in relation to limestone | Carbon in air gradually becomes locked up in sedimentary rocks as CARBONATES and FOSSIL FUELS Hydrocarbons were made from the remains of plants and animals Limestone from the shells and skeletons of marine organisms. |
| Positive aspects of exploiting limestone and producing building materials from it | - Building materials - Provides jobs - People use money to buy items in shops, boosting economy - Can turn into nature reserve |
| Negative aspects of quarrying | - Sound pollution - explosions - Visual pollution - Dust pollution - asthma - Global warming - vehicles - Congestion, local roads - Habitats |
| Evaluate the advantages of exploiting metal ores | Useful products made Creates job, brings money into economy Can be used to improve country services |
| What does mining involve? | Extracting (digging up) and processing large amounts of rock |
| Disadvantages of mining | - Subsidence creates holes (dangerous disused mines) - Limited - Habitats destroyed - Noise, dust and pollution - increases traffic |
| What happens if you recycle metals? | - Saves energy which comes from fossil fuels - Burning fossil fuels = gw - Reduces pollution of air and landfill - Reduces expensive energy - Uses only a fraction of energy used to make new metal - Conserves resources |
| Why use/not use metals in building? | Use: - Copper wiring - doesn't rust,bends - Lead: Roof work - Steel girders - Aluminium - corrosion resistant Negatives of use:: - Rust = collapse - Expensive than concrete - Uses up limited sources |
| Impact on the environment of burning hydrocarbon fuels | - Carbon dioxide emission (GW) - Carbon monoxide (toxic) - Sulfur dioxide - acid rain |
| Ethanol fuel production | 1) Biomass method using genetically modified E. coli bacteria, converts cellulose to ethanol - Can use any crops, renewable - its slow |
| Hydrogen as a fuel | Advantages: - Wastes very little energy - hydrogen + oxygen -> water + energy - Almost renewable Disadvantages - Leaks can cause explosions - Specially modified engines required - Not many filling stations - Electricity required to get hydrogen |
| Ethanol as a fuel: Hydration method | 2) Hydration with ethene (but ethene is from crude oil cracking, non renewable, but it's economic) - No waste products, H reused |
| Ethanol as a fuel: Fermentation method | 3) Fermentation - Renewable resource - Carbon dioxide - GW |
| BIOFUELS impact | NOTE: ETHANOL/veg oil blended with petrol or diesel for use in normal engines Pros - Oil conserved - More oil for other purposes e.g. medicine - Release less CO2 Cons - Food shortages - Land cleared for biofuel crops |
| Products of combustion - ethanol | COMPLETE combustion Ethanol + oxygen -> CO2 + water INCOMPLETE COMBUSTION Ethanol + not enough oxygen --> CO + soot + water |
| Equation for fermentation | |
| Equation for hydration | ETHENE + STEAM -> CATALYST -> ETHANOL |
| What is crude oil used for? | To produce chemicals and fuels but it is a limited resource |
| Benefits of using polymers | - Light - Non - toxic - Strong - Easy to shape |
| Cons of using polymers | - Wastes oil - Litter if don't degrade - Hard to recycle - Landfills |
| Comparing ethanol fuel sources | Hydration is non-renewable - Uses expensive high temperatures - Pure ethanol Fermentation is renewable - Less expensive - Have to purify ($$$) |
| Plant oils - effects on diet and health | Veg oils havea lot of energy - fried food lead to obesity Tastier food, cooks more quickly Unsaturated fats increase HDL AND reduce cardiovascular risks |
| Emulsifiers - evaluation | - Tempting to eat, creamier, thicker - Eat too much fatty food |
| Wegener's revolutionary theory wasn't accepted initially because... | - Was not a geologist - Tectonic plates not discovered - Maybe sea level dropped, causing animals to migrate? - Didn't know bout convection currents |
| How did life start? | - Evolved elsewhere and travelled on meteorite to Earth - Started by chemical reactions - We still don't know how these turned into cells - We can't know for certain what gases were present |
| Why can't scientists predict volcanos/earthquakes? | They are random! Scientists can use markers to monitor movement. |
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