Classifying materials lesson plan
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- All students know how solids, liquids and gases can interchange
- Most students to know how the Periodic Table can be used
- Some students to use chemical formulae and word equations
- Copies of Periodic Table for students. Demonstrations of filtering, chromatography, evaporation and distillation, with explanation cards
- Recap solids, liquids and gases, and their properties. Show how particles are arranged in the different states. Ask students to explain / match prepared explanations for why these behaviours occur.
- Explain the concept of an element, and give out copies of the Periodic Table. Explain what it shows, and that elements are grouped in relation to patterns of physical properties and behaviour. Explain these properties for Groups 1,2,7 and 0 (colour in and write on Periodic Table). Explain use of chemical symbols.
- Q. Is everything around us an Element? Guide students to conclude that many objects around us are not elements. State that reactions between elements cause Compounds (definite compositions- liken to baking a cake). Give common compound examples.Give examples of reactions using word equations. Students practise writing more. Explain use of chemical symbols in compounds. Students practise writing chemical formulae.
- Light waves; Use a circus of demos to illustrate properties of light waves. Students should work round in pairs or small groups and write down what they see. They could be given a list of properties to try and match them with.
- ray box / torch-light passing through a hole/shadows (light travels in straight lines)
- various objects with different degrees of shine (smoother plane surface reflects light rays)
- ray box showing light beam passing through glass block (refraction). Alternatively use a tall water-filled vase and look at the ‘straightness' of a ruler dipped in it.
- A crystal or prism which reflects rainbow colours (white light is dispersed to give a range of colours
- torch with colour filters (can use cellophane) white paper and different coloured objects (seeing colour). Use printable worksheet to reinforce understanding.
- Use an oscilloscope to illustrate how frequency of waves and pitch and the amplitude of vibration and loudness. Alternatively the students could try to feel the differences in vibrations on blown-up balloons. Extremes of pitch and amplitude would need to be used to tell the difference. Draw sound waves of different pitch and amplitude to illustrate difference.
- Ask if everything which is mixed together forms bonds and becomes a compound. Can a compound be separated back into its original elements? Why can certain mixtures be separated then? Conclude if bonds do not form between atoms of elements, a mixture is formed which can be separated. Show a circus of demonstrations of filtering, chromatography, evaporation, distillation. Students draw and describe each method.
- Give a list of mixtures. Students explain which would be the most appropriate method of separating them.