atomic structure Hypothesis Particle physics
Age Group
11 12 13 14 15 16
Expected time
1 period
The mysterious atom.PDF
beaker symbol

The Mysterious Atom

What’s the mystery? What is inside an atom, and how can we find out? Our ideas of atomic structure have changed over time as scientists have made observations and hypotheses, tested their ideas and come to conclusions. This process is still happening at CERN as particle physicists continue to unravel our understanding of the mysterious atom.
Domain(s) Physic
Subdomain keywords Particle physics, atomic structure, hypothesis.
Age group 11 to 16 years old.
Expected time for the mystery Approx. Time for teacher preparation -­ 1 hour
Approx. Time in classroom -­ 1 50 min lesson
Safety/supervision None
Disclaimer: The authors of this teaching material shall not be held responsible for any injury or damage to persons or properties that might occur in their use.
Preparation and list of materials Before the lesson:
For the Engage:
A mystery box or tube needs to be prepared. You can make one or several depending on time and budget.
The simplest idea is a sealed box with an unknown object inside. A few can be made which can be passed around the class. See the resources section for more information.
For the Explore:
On a desk place a sheet of black sugar paper -­‐ as large as possible. On top place a perspex block (e.g. the type used for optics experiments) and secure to the paper with blu-­‐tack so it does not move. Place more blu-­‐tack on top of the block and stick an A4 sheet of card on top of this so the block is hidden.The mysterious atomSet up one set of this equipment for each small group of students (each should have a different shaped perspex block if possible).
Each group will also need some marbles/ball bearings of different sizes, a small dish of talcum powder and a piece of chalk.
Learning objectives Students will :
Describe how scientists propose theories about the atom using the processes of observe, hypothesise, test, and conclude.
Resources Science museum mystery boxes

  • You can create a version of these for the Engage activity. Instructions can be found by going to and searching for ‘mystery boxes’. Download the pdf ‘Make you own mystery boxes’.

Mystery tube
Various online videos are available which show you how to make these. They range from quick and cheap to more elaborate versions.

  • Rutherford’s experiment
    Go to and search for ‘Rutherford’s experiment’.

Information about CERN

Dark matter video

Authors Gemma Young and John Walker -­‐ Sheffield Hallam University