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Author: Admin | 2025-04-27
Easily. Separating minerals by flotation Separating peanuts and raisins You will be working in pairs for this activity. You need to observe carefully and explain your observations. A video of this activity can be found here. The focus of this activity is to illustrate the principle of flotation and for learners to practice explaining their observations. They will have to apply what they know about density to be able to explain what they see. This activity can also be modified by letting the learners predict what they think will happen before they add the peanuts and raisins to the tap water; and again before they add it to the soda water. The outcome might not be what they expected and the value of the activity is for them to try to explain what they see. The peanuts will float because they are oily and the bubbles stick to them. This reduces the density of the peanuts so that they are able to float. The activity can be done as a classroom demonstration, but it is more effective if done by the learners in pairs. The one learner can use the tap water, and the other the soda water. A suggestions is to buy packets of peanuts and raisins separately, otherwise oil from the peanuts can coat the raisins, causing some of the raisins to rise. The raisins can also be rinsed in acidulated water because they are often dressed with oil before sale for visual enhancement. MATERIALS: peanuts raisins soda water tap water two tall glasses or beakers INSTRUCTIONS: Pour tap water into the first glass until it is about ¾ full. Add a handful of the peanuts and raisin mixture to the water and note what happens. Pour soda water into the second glass until it is about ¾ full. Add a handful of the peanuts and raisin mixture to the soda water and note what happens. Write down your observations. Explain your observations. Peanuts and raisins. Separating peanuts and raisins. Looking down into the water filled beaker. Use the following space to record and explain your observations. Learners
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