Unit 4 Application exercises

Qn 1: (a) Exothermic process. The heat that is released by the briquette can be felt in the surrounding. (b) Endothermic process. The water molecules must take in heat energy (increase in kinetic energy) in order to evaporate. (The skin gets cooled as water evaporates). (c) Endothermic process. The ice will take in heat energy from the warmer surrounding, causing… Read more →

The Ozone Layer

  The Ozone Layer helps by absorbing UV rays from the sun to reduce the heat from the sun to the surface of the earth. The production of CFCs(Chlorofluorocarbons) in the 1950s made the ozone deplete due to the CFCs breaking down Ozone in the stratosphere as shown below:   Read more →


Fig. 1: Ozone in the earth and atmosphere [1] Today, I have learnt that ozone is useful in stratosphere as it helps absorbs some UV radiation. I have also learnt about the wavelengths of gamma rays, UV, visible light, infrared radiation etc.   Reference: WeatherSTEM. (2017). Ozone – Good up high, bad nearby!. [online] Available at: https://learn.weatherstem.com/modules/learn/lessons/93/07.html [Accessed 1 Feb. 2017]. Read more →

Global Warming

The ozone layer is found primarily in the stratosphere of the earth’s atmosphere. It functions to protect humans from the harmful Ultraviolet rays from the sun by absorbing these rays. However, the addition of chlorofluorocarbons from a variety of goods such as aerosol sprays and refrigerants into the atmosphere has increasingly destroyed the ozone molecules in the ozone layer. Over… Read more →


Today we learnt about the ozone layer. The ozone layer is important because it helps to absorb UV radiation emitted by sun rays; like how a sunscreen works. However, if the ozone layer is depleted, it will become harmful to our environment  Ozone is O3. Read more →

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