Human Impact on Energy Flow –key-page 6

2a) Smog production is linked to energy transformation as burning fossil fuel produces smog.

Fossil fuel combustion (chemical energy) ---polluting gases (smog)

b) Smog can cause or aggravate health problems such as asthma, emphysema, chronic bronchitis and other respiratory problems as well as eye irritation and reduced resistance to colds and lung infections.

4) Learning from the past is important to our energy future as we do not want to create the same pollutants and hazards to the Earth.

5a) Cement plants account for 5 percent of global emissions of carbon dioxide

Fuel Cell technology produces zero carbon emission

b) Cement production has a greater effect on the atmospheric concentration of carbon dioxide as it produces this gas

13a) Carbon dioxide and natural gas (methane)

b) A quarter to half of Earth's vegetated lands has shown significant greening over the last 35 years largely due to rising levels of atmospheric carbon dioxide

c) Carbon dioxide is causing the Earth’s temperature to increase too much.

14a) methane cracking:

The researchers have refined a process known as methane cracking by using a continuous reactor of molten tin to produce hydrogen and high-quality black carbon without the problematic contamination by carbon monoxide, and even better, with virtually no carbon dioxide emissions

CH4+74.85kJ/mol⟶C+2H2

b) steam methane reforming:

Steam-Methane Reforming ReactionCH4 + H2O (+heat) → CO + 3H2

c) Which process is more harmful to the environment?

Steam reforming has two major drawbacks: it requires more energy than methane cracking, and it produces carbon dioxide.

15) Technologies with negative effect: motor car and coal power production: produce greenhouse gases.

35a) 90% of remaining energy goes into heat (thermal energy)

b) Yes I would choose LED bulbs. Although they are more expensive, LED lights last longer. The only drawback is that LED bulbs contain mercury, a toxic element.

c) No, most people would choose incandescent light bulbs because they are cheaper.

37a) If there is an accident at a nuclear power plant, radioactive particles are emitted into the environment and these particles have very long half live.

b) The carbon dioxide produced is a greenhouse gas which contributes to global warming.

In addition, carbon dioxide is acidic and it changes the acidity of lakes, rivers and oceans.

When this gas is dissolved in the marine environment, it dissolves marine sediments creating more greenhouse gases.

c) Fossil fuels electrical production is far more damaging than producing electricity from nuclear power plant. In addition, One gram of uranium yields about as much energy as a ton of coal or oil. Nuclear power plants do not produce greenhouse gases. The only draw back from nuclear power plant is the radioactive waste as well as possible accidents at nuclear plant.