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Models of the atom from Democritus to Rutherford

Levels: 5-6
NoS achievement aims: Understanding about science icon. Understanding about science , Communicating in science icon. Communicating in science
Contextual strands: Material world icon. Material world
Topic: Atoms, ions, molecules


The atom is composed of many different kinds of sub-atomic particles which are arranged in particular ways.

Scientific knowledge about the atom has evolved as new evidence has been discovered. The discovery of sub-atomic particles changed how scientists view the atom. This is an area where students can gain an understanding of how science ideas change over time.

What you need


  • How would early scientists have shown that matter was made of units too small to be seen?
  • Why do you think scientists’ views of atomic structure have changed over time?
  • How do scientists develop ideas about structures that are too small to see with the naked eye?
  • Have scientists’ ideas about atoms changed over time only because their instrumentation has become more powerful?
  • What might drive scientists to keep looking for new explanations?


  • Get students to read and/or act out the play.


  • Why do we need more than one type of model for complex phenomena? (No one model can represent all the features of a reality. Where something is complex, scientists pick the model that is most relevant to the aspect under investigation.)
  • How do scientists use other ideas to develop better understanding? (For example, they build on other ideas either directly or by challenging them.)
  • Do scientists have a complete understanding of the structure of atoms and how they act?
  • How do models help scientists understand the complexities of subatomic particles?
  • If you were going to extend this play to the modern day, whose ideas would you include, and why? (For more on atomic models see Selecting models of atoms .)

Activity resources

Word icon. From Democritus to Rutherford - Developing our understanding of atomic structure (a play) (Word 53 KB)