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Hard Stuff

Learning objectives

Students will:
• Work out how scientists created a new super hard material by studying data and using creative thought

Try the activity

• Hard stuff activity
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• Hard stuff teachers notes
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You will need Acrobat Reader installed to open the activity sheets.

Curriculum link

14 – 16 How science works: data, evidence, theories and explanations
1b How interpretation of data, using creative thought, provides evidence to test ideas and develop theories.

14 – 16
Chemical and material behaviour
6d the properties of a material determine its uses.

Please see downloadable teachers notes for more details of individual specificiations.

Running the activity

Display page 1 to set the scene and introduce the challenge.

Display page 2, which explains why metals like tungsten and titanium – and non-metals like diamond – are hard. In the new material, the metal rhenium makes the material hard to compress. The non-metal boron was also chosen as it forms strong bonds with rhenium, and can form a hard crystal under the right conditions.

Page 3 prompts students to plan questions for the journalist on page 1 to ask the team of scientists. Two questions are given already. Student groups make up two more questions focussing on:
• The data the scientists studied
• How the scientists thought creatively about the data to come up with the pair of materials in the new super-hard material

Students then speculate about answers the scientists would give to the four questions.

Students can record their questions and answers on page 3 if you wish.

Notes:
Diamonds are actually the hardest naturally occurring material, and the third hardest material. Two artificial materials – aggregated diamond nanorods and ultrahard fullerite – are stronger than diamond, but like diamond both are made from carbon.

Diamond cutting tools cannot be used to cut iron or steel as the carbon in the diamond reacts to form iron carbide, wearing the tool down and strengthening the material being cut.

Extension Activity 1: Other Designer Materials include Thinsulate™, Composite Carbon Fibres, Kevlar™ and Gore-Tex™. Students could be set a research task to find out what properties scientists wanted in those materials and how they used scientific knowledge and creative thought to invent them.

Extension Activity 2: Students can carry out a practical activity using their creativity and scientific knowledge to make a "designer material" with improved strength.
• Make a rectangular mould (plasticine works well) into which plaster of Paris is poured (petroleum jelly inside the mould may help remove the plaster of Paris easily).
• When set, remove the "bar" of plaster of Paris from the mould, and raise the ends of it above the desk (e.g. on two blocks of wood).
• Add masses to the bar until it breaks.
• Repeat, with students choosing other materials to add to the plaster of Paris – e.g. thin layers of muslin, spaghetti, string etc.
• Please note that CLEAPPS recently sent out a warning regarding plaster of Paris, details of which are here: http://www.cleapss.org.uk/secfr.htm

Web links

News links

New Scientist

Article about the new material

Sarah Tolbert

The scientist's web page

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