Science at key stage 3 (Year 8)
Unit 8E: Atoms and elements
Section 2: What are elements made from?
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Objectives |
| Children should learn: |
- to distinguish between elements and other materials
- that each element is made up of one sort of particle and these are called atoms
- that models can be used to illustrate phenomena that cannot be observed
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Activities |
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Outcomes |
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Children: |
- Use a model-building-brick system to show that there is a limited number of types of brick out of which everything can be made. Explain that we believe that everything in the universe is made out of a limited number of building blocks, but the diversity of things is determined by the ways in which these blocks are assembled.
- Model elements and other materials by showing pupils structures or materials made of only one kind of brick and others made of several. Ask them to decide and explain which are like elements and which are not.
- Take some objects made of only one type of brick and pull them apart until they can't be pulled apart any more. Explain to pupils that if you take a piece of element,
eg aluminium or carbon, and pull its particles apart like the bricks, you would end up with a pile of the smallest particles of the element that can exist. Scientists call this particle an atom.
- Check pupils' understanding that elements are made of one kind of particle only by asking them to draw pieces of a few named elements, then draw the individual atoms after the element pieces have been pulled apart as much as possible. Ask pupils to label the atoms and the elements and write about what the two words mean in science. Extend to models of non-elements.
- Introduce the idea of a chemical symbol representing an element,
eg by displaying some samples of elements with the symbols attached.
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- show by their drawings that they have some understanding of the relationship between elements and atoms and between elements and non-elements
- recognise the symbols for some elements
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Points to note |
- Throughout this unit it may be helpful to emphasise that classification of materials is a way of making sense of the wide variety that exists.
- It is important that pupils realise it is a material, and not an object, that is being modelled. Teachers could use other models,
eg atom/molecule kits, models of crystal structure, ICT simulations, as alternatives or additions.
- Many pupils will not arrive at the correct understanding about elements and atoms immediately. It may be helpful to make it explicit to pupils that these ideas become clear as they use and become more familiar with them.
- Some teachers may wish to introduce the idea that the symbol represents one atom of the element, but others will not feel it necessary at this stage.
- Teachers may wish to explore some of the limitations of the model with some pupils,
eg you can build many 'materials' from one size of red brick, but one type of atom forms one element.
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This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
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