UNIT 6: MATTER AND MATERIALS 1.- What are you going to study? 2.-Find the words. You can use your dictionary or a computer. MAIN LANGUAGE
6.1 MATTER. 6.2 PURE SUBSTANCES AND MIXTURES. 6.3 MATERIALS. 6.4 NATURAL AND MANUFACTURED MATERIALS. 6.5 THE THREE R’s.
UNIT 6. MATTER AND MATERIALS. 6.1 MATTER. Look at the picture. Can you describe any of the materials you can see? What are they made of?
Matter is all around us. Everything on Earth, and in the Solar System is made of matter. We’re made of matter too. Matter is everything that we can touch, smell, taste and see. Matter has mass and volumen.
Mass is how much matter an object has. We can measure mass in grams and kilograms.
Volume is the amount of space that matter takes up. We can measure volumen in litres.
6.1.1. STATES OF MATTER
Solid : the state of
matter with a definite shape and volumen. The molecules of a solid are very close.
Liquid: they do not have a definite shape. So, they take the shape of the container but have a definite volumen. The molecules are further apart than in solids.
Gases they do not have a
definite shape nor a definite volumen. If you keep gases in a container and open it, the gases expand as the molecules are very far away from each other.
6.1.2. CHANGES IN MATTER PHYSICAL CHANGES: are changes that affect to the traits of an object that we can see such as size, color, quantity or state. Physical changes can be caused by motion, pressure or temperature. It doesn't affect to the chemical composition of the substance. For instance if we cut a piece of paper into little pieces they change the quantity and the shape but they are still paper.
CHEMICAL CHANGES: are changes that affect to the molecules of the matter and a new substance is produced. So, chemical changes can not be reversed. Chemical changes can happen when we burn a substance or expose a substance to air. For instance if we cut an apple and wait for 30 minutes what happens????
6.2.- PURE SUBSTANCES AND MIXTURES. In nature, matter can be a pure substance or a mixture. Pure substances are formed from just one type of matter, such as salt, water and oxygen . Mixtures. Mixtures are formed from various components or various types of matter. For example, salt water is a mixture of water and salt. Air and honey are also mixtures. Sometimes you can see the different components in a mixture and sometimes you can´t. So we classify the mixtures into:
Heteregoneous mixtures: it’s easy to see the components.
Homogeneous mixtures: it is not possible to see the components. For instance solutions.
6.3.-MATERIALS. Materials are substances we use for building, making tools, making clothes, etc. All materials have different properties which make them useful for a specific purpose.
Steel is strong and resistant: it does not easily change its shape. It is used to make bridges. Leather is flexible: you can bend it and it does not break. It is used to make clothes, shoes…. Rubber is elastic: you can stretch it and change its shape, but it goes back to the original shape. It is used to make toys, balls, jewels, bags, shoes…. Glass is transparent: light can pass throug it and you can see through, It is used to make windows, glasses, Plastic is waterproof: water can’t pass through it. It is used to make raincoats, pipes etc. Pottery is fragile. It breaks easily. It is used to make cups, plates, pots….
QUESTION:
Why is paper good for making origame shapes? Make a list of its properties.
6.4 NATURAL AND MANUFACTURED MATERIALS
Naturals materials come from nature. They come from plants, animals or minerals. Wood, cotton and natural rubber come from plants. Wool, leather and silk come from animals and rocks and oil come from minerals.
Manufacture materials are made from natural materials which are transformed in a manufacturing process. We manufacture glass from sand.
6.5– THE THREE Rs. The three Rs are Reduce, Reuse and Recycle. These are the ways that we can be responsable consumers of the natural materials. Natural materials can run out if we don’t consume them responsibly.
Reduce the amount of materials we use and reduce the waste we produce. Buy products you really need with Little or nor packaging. Reuse means using something again instead of throwing it out. We can use plastic shopping bags again, or use shoes box to keep our crayons. Old glasses can be reuse by people who need them.
Recycle means to make new products from something we have used. We turn them into another material or product. For instance we recycle the plastic, batteries or aluminium to make new products.