Chemistry - Classifying Materials - offline version

Objectives:

• 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

National Curriculum:

Resources required:

• Copies of Periodic Table for students. Demonstrations of filtering, chromatography, evaporation and distillation, with explanation cards

Teaching Activities:

Introduction

1. 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.



2. 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.



3. 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.

Summary

• 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.

Suggested homework:

• Give a list of mixtures. Students explain which would be the most appropriate method of separating them.