Month: February 2017

Water For Life (session 5 unit 5)

How can you purify your water when you are hiking? Name two or three possibilities.Compare these methods in terms of cost and effectiveness. Are any of these methods similar to those used to purify municipal water supplies? Explain.   One of the method used is purification with iodine, however people with thyroid issues and expecting ladies should not use this method… Read more →

Global climate change

Understanding Earth’s energy balance is essential to understanding the issue of global warming. For example, the solar energy striking Earth’s surface averages 168 watts per square metre (W/m2), but the energy leaving Earth’s surface averages 390 (W/m2). Why isn’t Earth cooling rapidly? The emitted heat energy is mainly retained by the atmosphere thus the Earth does not cool rapidly even though the… Read more →

Energy from Combustion!

Question 1 A. A charcoal briquette burns Exothermic. As it burns, heat is released. B. Water evaporates from your skin Endothermic. For evaporation to occur, water absorbs the necessary heat from the surroundings C. Ice melts Endothermic. Melting occurs when ice absorbs heat from the environment Question 2 Q: Chemical explosions are very exothermic reactions. Describe the relative bond strengths in… Read more →

Ozone

The ozone layer is an important layer in the Earth’s atmosphere. It is primarily contained in the stratosphere, about 90%. There are about 3 molecules of ozone per 100 million molecules which makes the concentration of ozone very low. It helps to absorb UV-B and all UV-C rays which are detrimental to human health and can cause skin cancer.   Read more →

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