Charlie and the Chocolate Factory - States of Matter
Charlie and the Chocolate Factory by Roald Dahl provides a good context to learn about states of matter. This children's classic starts with Willy Wonka, the reclusive and eccentric chocolate maker opening his doors to five lucky members of the public – all they must do is find a Golden Ticket in their Wonka chocolate bars. Charlie Bucket, along with his unworthy fellow winners Mike Teavee, Veruca Salt, Violet Beauregarde, and Augustus Gloop, step through the factory gates to discover a world of chocolate rivers, boiled-sweet boats, magic chewing gum, square sweets that look round and Oompa-Loompas. Life will never be the same again. This book is a good setting through which children might:
- compare and group materials together, according to whether they are solids, liquids or gases
- observe that some materials change state when they are heated or cooled, and measure or research the temperature at which this happens in degrees Celsius (°C)
- identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature.
- Key scientific vocabulary: states of matter, solid, liquid, gas, change state, ice/water/steam, water vapour, heated/heating, cooled/cooling, temperature, degrees celsius, melt, freeze, solidify, boil, evaporate/evaporation, condense/condensation
Other fiction books with a similar theme include: The Snow Queen by Hans Christian Anderson and Bartholomew and the Oobleck by Dr Seuss.
At what temperature does chocolate melt?
A resource published by the Brian Cox for the Royal Society. The children conduct a fair test to see if different types of chocolate melt at the same temperature? Plain, milk and white chocolate have different percentages of cocoa solids, which gives it a different chemical makeup. Different brands of chocolate also have different amounts of cocoa solids. Does this affect its melting point? This resource includes a series of videos and lesson plans.
The children could think about what is needed to make the chocolate melt. They could then investigate how other food solids behave when they are made hotter? Does all food melt?What happens when they cool down again? What changes do they see?
Understanding Reversible Change
Through the heart of Willy Wonka's factory flows a river of melted chocolate. In this video we see a master Chocolatier who discusses his job and how he creates chocolates. He also talks about what he enjoyed at school and why he chose his career. The children could consider how the chocolatier works scientifically each day in his job? Which skills is he using?
This is a great example of a reversible change. Children could watch the video and then use the film to create their own chocolate cycle solid - melt - solid. They should identify the factors which cause a chocolate melt or to become solid. The children could experiment, creating their own chocolates and perhaps sell them in an enterprise project.
Terrific Scientific - Water
In this lesson from the BBC Terrific Scientific campaign, children investigate the Mpemba effect.Mpemba is a boy who in 1963 when making ice-cream observed that the milk that was hot freezing first. This has become known as the Mpemba effect.
Your children could investigate whether the mpemba effect is true or not. They could also investigate how other liquids freeze? Which liquids can you freeze in your school freezer? Which liquids don't freeze? This film is for teachers to help them think bout this freezing liquids in more detail. A great example in this film is of frozen lemonade, the carbon dioxide dissipates leaving a lattice of holes. The children could suggest ideas about why this might have happened.
Food for thought: food science
Who is a fan of fizzy drinks and sizzling sherbet? What is it about these things that makes them fizz and bubble? Have a go at making your own fizz and find out more about the science behind it. Sherbet powder is made from sugar, citric acid and bicarbonate of soda. When does sherbet powder fizz? Is the ‘fizz’ the same as in fizzy drinks?
Also see this article exploring popping candy.
