Chemistry inside materials 0.0 / 5 ? BengaliTopic 2OtherOther Created by: stephy08lamplCreated on: 20-05-14 08:21 What do most gases exist as? molecules 1 of 29 What do scientists use to represent molecules? Formulae 2 of 29 What do little numbers represent in formulae? The number of atoms in the molecule 3 of 29 How are the atoms in molecules joined? They are joined strongly together 4 of 29 How do you split up molecules? Chemical reactions 5 of 29 Is it difficult or easy to spilt up molecules into seperate atoms? Difficult 6 of 29 Why do gases diffuse? Because their particles are not attracted to each other 7 of 29 What do gases consist of? Tiny particles 8 of 29 How do particles diffuse? The particles are seperate from each other and they move around quickly. As they move around they spread out or DIFFUSE 9 of 29 What is the atmosphere? A layer of air that surrounds the Earth which contains gases that living things need, and helps to keep the Earth warm enough for life 10 of 29 What is the composition of the atomsphere? 78% Nitrogen, 21% Oxygen, 1% Argon, 0.04% Carbon dioxide 11 of 29 What has changed the atomsphere? We have burnt fossil fuels and cut down trees which adds carbon dio 12 of 29 What is a molecule? The smallest part of a substance that can take part in a chemical reaction 13 of 29 What is a polymer? A long molecule made up of many small molecules joined together 14 of 29 What is a monomer? A small molecule that can bond to others like itself to form a polymer 15 of 29 Name some natural polymers Cotton, silk, rubber, wool 16 of 29 Name some synthetic polymers PVC, polythene, polystyrene, polyester 17 of 29 How are natural polymers made? In chemical reactions in plants and animals 18 of 29 How are synthetic polymers made? By people and machines using chemical reactions in factories and science labs 19 of 29 Name a biologic polymer DNA, protein 20 of 29 Why is copper strong? Because the atoms are strongly attached to each other and are difficult to seperate 21 of 29 Why is copper bendy? Because its atoms are arranged in layers so they slide over each other when you bend the copper 22 of 29 Why does copper conduct heat well? Because the atoms are close together so when one atom vibrates it can easily pass on its vibrations to the next atom 23 of 29 Why does copper conduct electricity? Because the electrons are free to move 24 of 29 How are the particles arranged in salts? Alternately in rows. They are held together in a grid-like structure 25 of 29 Why is sodium chloride brittle? Because of the regular arrangement, it is easy to break along certain lines of the pattern 26 of 29 What keeps the sodium and chlorine particles in place? The strong attraction between them 27 of 29 What is the independent variable? What we choose to change 28 of 29 What is the dependent variable? What we measur e 29 of 29
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