Year 2 Science Uses of Everyday Materials – Block 2UEM – Materials Matter

Session 6:Melting and Moulding
Science curriculum area(2UEM): / Content(2UEM)
i. identify and compare the suitability of a variety of everyday materials, including wood, metal, plastic, glass, brick, rock, paper and cardboard for particular uses
ii. think about unusual and creative uses for everyday materials
iii. find out how the shapes of solid objects made from some materials can be changed by squashing, bending, twisting and stretching
Working Scientifically (KS1 WS)
- skills explored withguidance / Working Scientifically (KS1 WS)
i) asking simple questions and recognising that they can be answered in different ways
ii)observing closely, using simple equipment
iii) performing simple tests
iv) identifying and classifying
v) using their observations and ideas to suggest answers to questions
vi) gathering and recording data to help in answering questions
Teaching Objectives /
  • To learn about what happens when a material is heated up and why it changes shape
  • To role-play what happens to the particles in a material when it is heated
  • To investigate the changes to wax crayons caused by heat

Key Vocabulary:material, properties, melting, particles, changing shape
Resources
Particles Role Play and Melting and Remoulding Wax Crayons resource, old wax crayons, plain paper and paper for writing on, silicone moulds, old mugs or jugs, scissors, knife, microwave. / Weblinks
- Desert Island Materials game.
Before the session:Collect old wax crayons together, ready for this session. Make sure you have a microwave available to use. The class will need to do this in small groups with an adult.
Whole class:Before the chn go into the classroom, ask them to go into the hall and act out what happens to particles when they heat up (when a solid melts) using the Particles Role Play resource. Then go into the classroom and explain that they will be investigating melting using wax crayons. Say:We are going to recycle our old wax crayons. We will heat them up in the microwave so that their particles move around and the solid crayons become liquid. Then we are going to pour the hot wax crayon into moulds and let them set. They will become new crayons in a different shape, ready to use again!
Activities:Explain that everyone will get a go at melting wax crayons and everyone will have the chance to do a challenge (extended writing) in the classroom. Challenge the chn to design a machine that heats up old wax crayons and remoulds them into usable shapes. The machine will need to be safe enough to stand in a corner of the school so chn can just pop their old wax crayons in whenever they break. Then ask the chn to write a letter to the dragons on Dragons' Den to persuade them to accept the designs, explaining firstlythe usefulness of wax crayons (not just for drawing but also for waterproofing materials and wax resist painting) and secondly why the machine needs to heat them up (so their particles can move around and settle into a new shape). Before setting the chn off on their designing and writing challenge, split the class into groups so they know when it is their turn to heat up the crayons. Ask an adult to take small groups out to the microwave with some wax crayons. They will need to follow the instructions in the resource sheet, starting by peeling all the paper off the wax crayon and cutting it into centimetre long sections with a pair of scissors (or knife under supervision). You may want to experiment with different shaped crayons by pouring the wax into an array of mould shapes and sizes. Put the filled moulds in the fridge to accelerate the cooling process but make sure the whole crayon is cold before you, and the chn, pop them out of the moulds.
Plenary / Ask the chn to try out the different shaped wax crayons. Ask them:Which shapes are more useful for holding and colouring? We have recycled our old wax crayons! What other materials do we recycle? Can you think of other examples of things that change shape and become something else, something useful? Why is it important to recycle materials?
Tell the children you are going to see if they have really become Material Masters during these sessions. Challenge them to play Desert Island Materials using the BBC link.
Give the children whiteboards to record their answers to each challenge. Ask them to show you their boards before you or a helper reveals the answer. Congratulate them on all their learning about the properties of everyday materials and how they have become expert Material Masters.
Outcomes / Children will
  • Understand what happens when a material is heated up and why it changes shape
  • Discuss the importance of recycling materials
  • Understand and experience recycling by remoulding wax crayons in new and different shapes

© Original resource copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.

We refer you to our warning, at the foot of the block overview, about links to other websites.