Objectives of the remodelled lesson
The students will:
Abstract
Students examine pictures of models of atoms, are provided with materials, and are asked to make their own models of oxygen, carbon, or sodium atoms. They are asked if they can make the electrons revolve. [From Concepts in Science: 6th Grade by Paul F. Brandwein, Elizabeth K. Cooper, Paul E. Blackwood, Elizabeth B. Hone. p. 293.]
Critique
This lesson fragment offers an opportunity for students to discuss the purposes of models in general and the specific benefits of making models of atoms. Students can also practice assessing models, in light of those purposes. By examining their models at length and in great detail, students can develop their clarity of thought and expression, and review what they know about atoms.
Strategies used to remodel
The class could begin by discussing models in general and analyzing the concept. "What does 'model' mean? What models have you seen or made? Did they help you understand what they modeled? How? Why? How can you tell a good model from a poor model? What's an example of a good model? Why? A poor one? Why? S-15 What differences were there between models you have seen and the things they modeled? (Ask this of several of the examples previously given.) Why make models? What purpose do they serve?" S-14
Tell students that they are going to make models of atoms. Have students discuss what they know about atoms, and ask, "How could models of atoms help us? How could we make a model of an atom?" You might ask them what parts they would need, and how they could put them together. S-1 Students could make and evaluate various models of atoms and engage in an extended process of designing, making, discussing, and improving models of atoms. S-8
Students could be led in a discussion of the strengths and weaknesses of various models, with questions like the following: (Of each proposed model ask,) What parts does it have? What parts do atoms have? Does the model have any extra parts? Does it leave out parts? How is each part of this model like the part of the atom? (Continue for each part, including the connecters.) Unlike? (Encourage multiple responses.) Could this model be improved? How? How do these models help us? How could they mislead us? How can we avoid being misled? S-10 Do these models help you understand atoms? How, or why not? Do any of these models suggest questions about atoms? What? Do the models help you find answers to those questions? Why or why not? Are the differences between the model and the atom relevant to the question you asked? Why or why not? S-31 How could this model be improved? Why would that improve it?
The teacher could use the idea of models to clarify the concept 'analogy'. Have students recall analogies. Have them compare models and analogies. (A model is a thing, analogies are words. Both have similarities and differences to the originals. Both can be evaluated in terms of their purposes and whether relevant features are similar or different.) S-23