​Unit 5 Energy

Energy exists in different forms. Common energy forms include chemical energy, electrical energy, kinetic energy, light energy and potential energy, etc. By the law of conservation of energy, energy can neither be created nor destroyed; it can only be changed from one form to another. With different energy converters, various forms of energy can be converted to other forms of useful energy at different efficiencies. Energy can also be transferred due to temperature difference by conduction, convection or radiation. A study of the factors affecting these energy transfer processes can enhance our understanding of their daily applications. Today, the world’s primary energy sources are fossil fuels. However, there are concerns about their limited supply and the related pollution problems. There is a need to reduce our energy consumption and develop alternative sources of energy, like nuclear energy, solar energy and wind power, etc.

In this Unit, students will learn the different forms of energy, energy conversion, energy transfer processes and the various kinds of energy sources. Through performing fair tests, and design and make activities, students can develop some science process skills such as designing investigations. By constructing Sankey diagrams, students learn to communicate scientific ideas through graphical representations. Students will realise the unifying concept “change and constancy” through the learning of energy conversion and conservation of energy.