The Chemist's tools 9.1.3 - The observations circus


Students should:

  • Understand that a chemical reaction involves the formation of a new substance
  • Realise that experimental skills involve careful observation and recording
  • Carry out a variety of different reactions and identify evidence for chemical and physical reaction


Matter: states and properties of matter.

Particle/kinetic theory, diffusion.

Pure and impure substances. Types of mixtures (solutions, oils, alloys, emulsions)

Separation techniques, including filtration, distillation [including crude oil - myp10], chromatography.

Activity - Qualitative observation:

Experiment 1 - The reaction circus

Experiment: Reactions circus


To learn the value of observing and recording observations in a logical manner using appropriate vocabulary. The students will probably not know many of the words they need to adequately describe what they see. (communication skills)

  • Observation (description) before.
  • Observation (description) during.
  • Observation (description) after.

Experimentation and instrumentation

The most important (but certainly not the most accurate) tools are our own senses, however these cannot be used empirically.


Student follow up

The experiments should be written up as a lab report and evidence for the chemical or physical nature of the reactions identified. An overall conclusion as to the ease of identifying by evidence should be included as well as an evaluation of the effectiveness of the experiment circus.

Teacher's notes

The sulfur experiment should be carried out in the fume cupboard.

Iodine finger may be placed in a beaker of sodium thiosulfate after the reaction is observed

Heat proof mats should be supplied for the iron nail


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IsisSoft 2014