Some students have difficulty letting go of Bohr’s model and do not easily adopt a new quantum model
In studies, this has presented in the following ways:
- Students do not accept that the electron cloud model is a model for the atom
- Students may develop new ideas of a quantum model but retain parts of the planetary model
- Students may think that electrons fly around the nucleus with high velocity in fixed, prescribed orbits. In this conception the centrifugal force and the Coulomb force are in equilibrium.
Even after quantum mechanics teaching, many students still describe an atom as ‘being’ the Bohr model.
Resources to Address This
To move the students beyond the Bohr model of the atom a quantum mechanical model is introduced. These materials outline the idea of matter waves, represented by probability equations which describe the likely positions of electrons and provide an introduction to quantum mechanical models before looking at the equations proper.View Resource
Electrons can be represented as standing waves and these materials provide support in that approach. Starting with a refresher about Melde’s experiment, setting up a standing wave in a string under tension the students move on to look at wire loops representing the electrons in atoms.
The resource also provides a set of calculations based on the information, linking to the de Broglie equation.View Resource
This resource provides an overview of the development of the atomic model. It can be used to check students’ understanding of the history of the development of the model, filling any gaps in their prior knowledge, before moving on to the quantum mechanical model.View Resource
- Tsaparlis, G. & Papaphotis, G. () High‐school Students' Conceptual Difficulties and Attempts at Conceptual Change: The case of basic quantum chemical concepts, International Journal of Science Education, 31 (7)
- Petri, J. & Niedderer, H., () A learning pathway in high‐school level quantum atomic physics, International Journal of Science Education, 20 (9)
- Fischler, H. and Lichtfeldt, M. () Modern Physics and Students' Conceptions, International Journal of Science Education, 14 (2)