The Significance and Characteristics of Atoms
|Issue||Naive Idea*||Scientific Idea|
|Composition of Matter||Molecules are in matter. Molecules of air, for example, are surrounded by air. *||All matter consists of molecules.|
|Size of Molecules||Atoms and inorganic molecules are the size of dust particles or can be seen with a microscope.
|Most inorganic molecules are too small to see by any known means.|
|Nature of Substances||Gases are somehow different from liquids & solids. Gases have no weight. **||The molecules of a substance remain the same through all state changes (solid, liquid, gas).|
* Harvard/Smithsonian Private Universe Group
** Michigan Group
* This table has been adapted from
Berkheimer, G. D., Anderson, C. W., Lee, O. and Blakeslee, T.
D. with assistance from Eichinger, D. and Sands, K., Occasional
Paper #121: Matter and Molecules Teacher's Guide: Science Book.
We are indebted to the authors for both their information about
alternative conceptions and for their idea of a 'conceptual contrasts'
table, which we will refer to as 'Alternative Ideas.'
Alternative ideas are known by many
names including alternative conceptions, misconceptions, and naive
ideas. They have been extensively studied during the past 15
years. These alternative ideas are shared by a significant fraction
of the population of students, often 20-60% of students in a class;
they are surprisingly resistant to being taught away (especially
with traditional, didactic teaching); and while some alternative
ideas are culturally bound, most appear in similar frequencies
in classrooms around the world.
This does not imply that all prior knowledge is faulty. Students have a great deal of valuable prior knowledge. A good teacher will draw out some of the students' prior experiences and link them to events in the classroom. Scientific understanding is strengthened when it is integrated with everyday knowledge.