Term 3 Topic 1 Burning Fuels IntroductionFuels need heat to set them alight and air (oxygen) to keep on burning.Teacher Input 7Teacher writes the following words on flard cards: burning fuels, energy and oxygen.The flash cards are used to explain what burning fuels require.The teacher tells the learners that burning fuels require energy from oxygen to start burning.Different types of gas are found in the air as follows:Nitrogen – 79%.Oxygen – 20%.Other – 1%.Show Video Clip 3 (4:27 minutes). Prepare the learners for the practical task that will follow.They are reminded to be observant so that their recordings can be accurate.Their attention is also drawn to safety precautions when working with matches and candles.Learner Activity 5This activity is a practical task that can be completed for marks.Divide the class into groups, however, learners should work on their own when they record information.Provide guidance where required, but remember they should be able to complete the activity on their own as they would have practiced it before.Each group conducts the experiment.Each group will need:A candle.Two glass containers of different sizes.Stop watch (a cell phone can be used).Method:Light the candle and then put the first glass container over it.Measure in time how long it takes the candle’s flame to go out.Repeat the experiment with the second glass container.Repeat the experiment without any container over the candle.Learners record their findings in their (Worksheet E).Learners provide feedback on their findings. Review their answers and correct statements as required.Introduce the concept of a HYPOTHESIS: Ask learners to make a sentence using “If”…and “Then”…Teacher Input 8Ask the following questions:What does a fire need to burn?Answer: oxygen, fuel, source of energyWhat did we need for the candle to burn in this experiment?Answer: Air (oxygen) to support the burningFuel (candle wax).Source of energy (burning match or lighter):How much of the air that are around us consists of :GAS FOUND IN THE AIRANSWERS IN %Nitrogen79%Other1%Oxygen20%Inform the learners that they will first watch a video clip about burning substances before they go to a demarcated section on the school ground to do an experiment.They are reminded to take note of the different substances and its effects.They are also informed that the burning would stop once the fuel or the oxygen has been removed.Introduce the Fire Triangle which requires all three sides of the triangle for combustion: Fuel; Oxygen and Heat. Learner Activity 6The following experiment must preferably be done on the school grounds under the strict supervision of the teacher.Equipment needed:a piece of wood and a candle – both items must be of the same weight; paraffin; matches & firelighter; candleholder.MethodLearners make their hypothesis whether the candle will burn out quicker or longer or at the same time as the wood.One learner can be asked to place the wood on the ground.The teacher pours some paraffin over the wood.The teacher sets the wood alight with a firelighter.One learner can hold the candle while another learner carefully lights the candle with a match at the same time when the teacher lights the wood.The learners compares the learners’ hypothesis with the results of the experiment to see who was correct or the closest.Learners record the information on this experiment in Worksheet F.Revision Activity 2Learners complete Quiz 2. By Administrator|2015-07-16T14:35:35+02:00July 16th, 2015|0 Comments Share This Story, Choose Your Platform! facebooktwitterlinkedinredditwhatsapptumblrpinterestvkEmail About the Author: Administrator Leave A Comment Cancel replyYou must be logged in to post a comment.