Mixtures – a chemistry unit

Mixtures is a chemistry unit requiring no specific prerequisite knowledge aimed at 11-14 year olds. It is written by a great team of science journalists from Cosmos Magazine in Australia.

This science unit is fully done online via a computer, laptop or tablet where students submit their answers and project work and it will get marked, usually overnight.
This science unit contains an introduction, four lessons with learning goals, four quizzes, two experiments, a project, a career part to connect science with society and a final test.

The fee to participate in this online science unit is $45 per student, which includes marking of the lessons, quizzes, activities, projects and final test. Access is during the first 5 weeks of term 2, 2016, from 25 July until 26 August.

Do note that you will need a few resources for the experiments in this unit. Most of these will be easily accessible, such as sugar, vegetable oil, mustard, salt, honey and detergent. For one of the experiments the student will need five small transparent containers with lids, they can be ordered if you can’t find anything suitable at a cost of $7.50 including postage.



Most of the of things around us are made up of different substances mixed together. By combining components in different proportions we can get very different results, many of them useful.

Lesson structure:

  • Introduction stimulates interest with a recent Cosmos Magazine article about ground-up cow bone used in 3D-printed bone scaffolds for accident victims.
  • Lesson 1 contrasts mixtures with pure substances, covers how mixture components can be solid, liquid or gas, and explores how component proportions change the properties of the resulting mixtures.
  • Lesson 2 covers suspensions and colloids, and introduces the importance of particle size in this distinction.
  • Lesson 3 introduces solutions and associated terminology. Differences in particle size are used to explain how solutions differ from colloids and suspensions.
  • Lesson 4 introduces the concepts of concentration and saturated and unsaturated solutions, using an interactive simulation for the latter. Concentration applies to colloids and suspensions too.
  • Science and society profiles a paint chemist. As a societal issue we consider what the blood alcohol concentration limit should be for driving.