1. There are a few ways to purify water during hiking:
– Sand filter,
– Purification tablet,
– Evaporation distillation.
All three methods are somewhat used by municipal water supplies. Sand filter is comparable to filtration; Purification table is comparable to coagulation; Evaporation distillation is comparable to industrial size distillation plant.

2. Because it is extremely expensive due to excess power requirements, and only affordable by rich country like UAE.

3. a) Because of the corrosion of lead pipes, solder found on drinking fountains of water tanks.
b) Most probably not since they should be using an isolated system away from the water system.

4. Based on the phrase ‘like dissolves like’, polar will dissolve polar and non-polar will dissolve non-polar. Therefore, water-soluble compounds are polar since water is a polar compound and fat-soluble compounds are non-polar since fat is a non-polar compound.

1. Because our atmosphere gases trap and return a major portion of the heat radiating from the Earth.

2. Global warming, as many people think, is a phenomenon that the temperature is increasing. Snowing in winter indicates the low temperature. However, snowing does not mean that it is not global warming.

3. Because water absorbs microwave radiation and therefore, weakens the signals given out by the devices.

4. In short run, air quality should be the problem. For example, if CO2 concentration increase 3 times, you won’t be able to survive in few minutes. In long run, global warming should be the problem since its effects take many years to surface.