Atoms Demonstrations

See also: Elements and Periodic Table, Nuclear Physics

Atoms are the basic units of matter that still retain the properties of an element. This category focuses on the structure of atoms, the particles they contain, and how they combine to form more complex substances. Learning about atoms helps explain the composition of matter and underpins much of modern science.

Demonstration	Materials	Difficulty	Safety	Summary
Cloud Chamber	★★★	★★★	★★★	A cloud chamber makes it possible to see the invisible tracks of cosmic rays and other charged particles as they pass through alcohol vapor. Using dry ice and isopropanol, students can build a detector that reveals trails left by subatomic particles.
Flame Tests	★★☆	★★☆	★★☆	Different metal ions produce characteristic flame colors when their solutions are heated in a flame.
Rutherford Scattering Analogue	★☆☆	★☆☆	★☆☆	In this analogue demonstration of Rutherford’s alpha particle scattering experiment, an aluminum pinnacle represents the atomic nucleus. Ball bearings, representing alpha particles, are rolled toward the pinnacle and are deflected in patterns that match Rutherford’s scattering theory, enabling students to visualize the discovery of the nucleus.
Methanol Flame Colors	★★☆	★★☆	★★☆	Metal salts are heated in burning methanol to produce vivid flame colors that correspond to electronic transitions in their ions.
Cylinder Puzzle Model of Scientific Inquiry	★☆☆	★☆☆	★☆☆	The cylinder puzzle is a hands-on activity to model how scientists work. Students investigate an opaque cylinder threaded with ropes. By pulling on different knots and observing the results, they form and test hypotheses about what is hidden inside. The puzzle highlights observation, explanation, prediction, and the limits of scientific certainty.
Making Marshmallow Molecules	★☆☆	★☆☆	★☆☆	This activity uses colored marshmallows and toothpicks to model atoms, molecules, and compounds. By assembling marshmallows to represent different elements and connecting them with toothpicks as covalent bonds, students can visualize how atoms combine to form molecules and chemical structures.
Brownian Motion in a Smoke Cell	★★★	★★☆	★★☆	This classic experiment demonstrates Brownian motion by observing tiny smoke particles under a microscope. Their random, jittery movement provides strong evidence for the particulate nature of matter and the constant motion of gas molecules.
Atomic Spectra With a Diffraction Grating	★★☆	★★★	★★★	Using a diffraction grating and a gas discharge tube, you can observe the unique emission lines of different elements. These distinct line patterns reveal the quantized energy levels of electrons in atoms.

Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories

Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher

Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff