Unit 2M.2: Investigating Materials

Transcription

1 Unit 2M.2: Investigation (1) Waterproof Materials Bendy and Flexible Materials (2) Shiny and Dull Materials Transparent and Opaque Materials. Science skills: Classifying Observing Predicting Measuring By the end of this unit you should be able to: Devise simple tests for some properties of materials Draw conclusions from observations and evidence. Make predictions about what might happen in an investigation and then test them. Be able to label pictures and make tables to record observations. 54

2 Materials 1 Investigating materials (1) Waterproof materials All materials have different properties. Being Waterproof is one of these properties. Waterproof material: Any material that doesn t let water through is called waterproof. We use waterproof materials in our daily life. Think and Discuss What material is an umbrella made from? Why?

3 Activity (1) This teddy bear wants to make an umbrella, but he doesn t know which material should be chosen. Help him to test these materials. Materials: dishcloth, tissue paper, a paper towel, aluminum foil, plastic sheet, cup, bowl Process Skills: predicting Steps 1- Choose one of the materials given and attach the material to the top of the cup with a rubber band as shown in the picture. 2- Place this in a large container or bowl. 3-Predict which material will not let water through. 4- Pour water over it on the material being tested. Observe. 5- Record your result. Waterproof Not waterproof Material Dishcloth Tissue paper Paper towel Aluminum foil Plastic sheet 56

4 , 2.1.2, Materials 1 Bendy and Flexible Materials Many materials around us are flexible. Flexible material: Any material that you can bend, squeeze, or stretch easily. Think and Discuss Which of these materials is flexible and which material is not flexible? Write your answer under each picture

5 Activity (2) Can you find a suitable material to make a see-saw for a teddy bears playground? Materials: Plastic rulers, metallic ruler, wooden ruler, piece of glass, piece of ceramic Process Skills: Predicting Observing Classifying Steps 1- Bend the ruler to test its flexibility. 2- Record what happened to the material during the test. Material Bendy Not bendy Plastic rulers Metallic ruler Wooden ruler Pace of glass Pace of ceramic WARNING! DON T BEND TOO MUCH IT MIGHT SNAP! BE CAREFUL Which material would be best for a see-saw for the teddy bears playground and why?

6 , 2.1.3, Materials 1 (2) Shiny and Dull Materials Shiny and dull are two words we use to describe the properties of certain materials. Shiny material: you can see your reflection in some of these shiny materials, and it is bright when light shines on it. Dull material: you don t get any reflection from dull materials, and it is not shiny even when light shines on it. Put a tick ( ) under to the shiny materials. 59

7 Activity (1) Can you set up a test to find out which materials/objects are shiny and which are dull? Materials: metal, wooden spoons, pans, shiny/glossy, wrapping paper, mirrors, woven or knitted items, shiny fabrics, aluminum foil. Process Skills: Predicting Observing Classifying Look at the objects and classify them into two groups shiny and dull. Before you start testing objects, think about the following questions: Can I see my face in it? Can I see other objects reflected in it? Does it reflect any light when you move it around? Fill in this table as you test each object. Write yes or no in the column. Materials Shiny Dull Wooden spoons Glossy wrapping paper Mirror Woven material Aluminum foil 60

8 , Materials 1 Transparent and Opaque Materials Transparent and opaque are physical properties of some materials. Can you think about the meaning of these words? Transparent material: you can see through it. Opaque material: you can t see through it. Translucent material: light passes through, but you cannot see through it. Think and Discuss Draw a circle around the transparent objects and cross the opaque objects. 61

9 Activity (1): In this activity you will test materials to determine whether they are transparent, opaque, or translucent. Materials: clear plastic sheet, papers, glass cup, tissue paper, a paper towel, aluminum foil Process Skills: Predicting Observing Classifying Steps 1-Try to look through each object. 2-Hold up something behind each object to see if it can be seen through the object. 3- Record your results. Tick the column. Materials Transparent Opaque Translucent Clear plastic sheet Papers Glass cup Tissue paper A paper towel Aluminum foil Conclusion:

10 Key terms: Names of properties: waterproof, flexible, shiny, dull, reflect, heavy, light, see-through (transparent), opaque (not see-through), translucent (light passes through, but you cannot see through it). Words relating to the investigative process: test, investigate, look, feel, measure, record, table, chart. Key ideas: Materials have different physical properties. Materials are chosen for different uses because of their properties. Key questions: 1-Draw and label a picture showing a test to find out how easy it would be to crush cups made of paper and plastic. Describe your test. 63

11 Key questions: A group of children tested some materials. Before carrying out the test they said the following things: Material A has two layers Material C feels soft. I can t see through Material D. I think Material A will let lots of water through, because it is covered in holes. Material C will be the best because it s made from plastic. I think Material B will not let any water through. Let s pour water on them to find out. Material D will be waterproof. Material B feels thick. Color the boxes that show predictions red (what they think will happen). Color the boxes that are observations green (what they notice about the materials). Color the boxes that plan how to test the materials blue. 64