Metals and Plastics In this section you will learn Metals/ non-metals. Uses of metals (5) Properties of metals (6) Properties of non-metals (6) Exp. Metal or non-metal use bulb circuit, 1 exception 4 examples of each. Alloys, examples (3), uses (3) reasons for making (2) Alkali group 1 metals, physical properties (4), chemical properties (4) Use of alkali metals (3) Reaction metals with acid, Zinc with hydrochloric acid, word equation + chemical equation D. Mac an Aircinn Coláiste Chiaráin

Metals and Plastics You will learn Four metals and exp. Show reactivity order with acid and water. Corrosion and exp. Show conditions needed for rusting (3 test tubes to set up) Rust prevention (3 ways) Plastics (examples 5), uses (5). properties of plastics (5) and how it affects their use (5) Problems of plastic for environment (2) D. Mac an Aircinn Coláiste Chiaráin

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Metals Properties of Metals Shiny appearance Lustrous Can be hammered into sheets Malleable Can be drawn into a wire Ductile Conduct electricity Conduct heat High melting points and boiling points High density, sink in water. Metals make a ringing sound when you strike them. Metals are strong D. Mac an Aircinn Coláiste Chiaráin

Non-Metals Properties of Non-metals Low melting and boiling points If they are solids they are not shiny Do not conduct heat or electricity They are not malleable or ductile. They are brittle They have low densities and are light Exceptions Carbon in the form of graphite is good conductor of electricity Carbon in the form of diamond is shiny and has a high melting point. D. Mac an Aircinn Coláiste Chiaráin

Metals You must know 2 examples of the colour and state of two metals and two non-metals. Write down 2 examples of metals and two non-metals now. Answers Metal colour state Gold yellow solid Copper brown non-metal Carbon black Sulphur D. Mac an Aircinn Coláiste Chiaráin

Metals Exceptions for metals Mercury is a liquid at room temperature Lead is a dull metal not shiny Calcium is a brittle metal The alkali metals have some very different properties as we will investigate now. D. Mac an Aircinn Coláiste Chiaráin

Metals Questions Are all metals solids at room temperature? List five properties of metals. How could you show metals conduct electricity? Name a dull metal. Some metals are soft name one. What does malleable mean? What does ductile mean? D. Mac an Aircinn Coláiste Chiaráin

Alkali Metals Honours Litium Sodium Potassium D. Mac an Aircinn Coláiste Chiaráin

Alkali Metals(Honours) Group 1 elements in the periodic table All very reactive so not found free in nature Like most metals they are shiny Like most metals they conduct electricity Unlike most metals they are soft (cut with a knife) Unlike most metals they have low melting points and boiling points. Unlike most metals they have low densities and float on water. D. Mac an Aircinn Coláiste Chiaráin

Alkali Metals (Honours) Chemical properties React with air to form oxides React with water to form hydroxides and hydrogen Metals burn with coloured flames D. Mac an Aircinn Coláiste Chiaráin

Alkali Metals (Honours) Reaction with air Lithium + Oxygen  Lithium Oxide Sodium + Oxygen  Sodium Oxide Potassium + Oxygen  Potassium Oxide D. Mac an Aircinn Coláiste Chiaráin

Alkali Metals (Honours) Reaction with water give hydroxides and hydrogen Lithium + Water  Lithium hydroxide + Hydrogen Sodium + Water  Sodium Hydroxide + Hydrogen Potassium + Water  Potassium Hydroxide + Hydrogen D. Mac an Aircinn Coláiste Chiaráin

Alkali Metals (Honours) Burning in air gives coloured flames Lithium burns with a red flame Sodium burns with a yellow flame Potassium burns with a lilac flame Uses of alkali metals Lithium in batteries Sodium in street lamps Potassium compounds in fertilisers. D. Mac an Aircinn Coláiste Chiaráin

Alkali Metals (Honours) What are alkali metals? Why are they so reactive? How are they different to ordinary metals? (3 differences) What do they form when they react with air? What is produced when they react with water? Give three uses of alkali metals. D. Mac an Aircinn Coláiste Chiaráin

Reaction of Metals with Water and Acids Zinc + Hydrochloric  Zinc + Hydrogen Acid Chloride You must be able to prepare hydrogen gas using zinc. Hydrogen gas burns with a loud pop when a lighted match is put to the mouth of test tube of the gas. D. Mac an Aircinn Coláiste Chiaráin

Reactivity of Metals (Honours) You must be able to put four metals in order of their reactivity. Look at the table and put the metals in order of decreasing reactivity. Metal Reaction with water Reaction with acid calcium Fast reaction Very fast reaction Copper none Magnesium Very slow Zinc Slow reaction The reactivity in order of decreasing reactivity is Calcium, Magnesium, Zinc and Copper. D. Mac an Aircinn Coláiste Chiaráin

Corosion of Metals Corrosion = When a metal is converted into one of its compounds Rusting = the corrosion of iron or steel Air/oxygen and water are needed for rusting. Prevention of Rusting (where used, problems, examples) Painting Oiling or greasing Galvanising D. Mac an Aircinn Coláiste Chiaráin

Rusting Rusting costs the economy millions every year D. Mac an Aircinn Coláiste Chiaráin

Investigating that oxygen and water are needed for rusting What apparatus and materials are needed. How are the nails stopped from getting water from the air? How are the nails stopped from getting oxygen from the air? Why is boiled water used in this experiment? How is oxygen in the water removed. What is the control for this experiment? D. Mac an Aircinn Coláiste Chiaráin

Investigating Rusting D. Mac an Aircinn Coláiste Chiaráin

Alloys What is an Alloy? Alloys have different properties than the metals that make them up. What does this mean? Why are alloys used for coins rather than gold and silver? Name two alloys and uses of those alloys? The melting point of solder is lower than that of the metals it comes from or used on. Why is this an advantage? D. Mac an Aircinn Coláiste Chiaráin

Alloys Alloy are mixtures of metals. Some alloys have carbon added steel for example. Alloys are used because they are stronger etc. Common alloys Alloy Mixture Use Brass Copper and zinc Door handles Bronze Copper and tin statues Steel Iron and carbon construction solder Lead and tin Join electric wires D. Mac an Aircinn Coláiste Chiaráin

Corosion What is corosion? What is the difference between corosion and rusting? Why is corosion a problem? What are the conditions needed for rusting to occur? How can you prove water is needed for rusting? W D. Mac an Aircinn Coláiste Chiaráin

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Plastics Plastics was used to describe substances that become soft when warm and their shape can be easily changed Most are made from crude oil i.e are synthetic, some are natural such as rubber which is obtained from a tree. D. Mac an Aircinn Coláiste Chiaráin

Properties of Plastics Can be moulded Do not corrode. Very cheap Low density, not heavy Good electrical and heat insulators D. Mac an Aircinn Coláiste Chiaráin

Uses of Plastics Wire and plug insulation Drinking cups, flasks because of bad conductors. Packaging, bottles, bags because of low density. Make buckets, basins, jugs, cups etc. because they are easily shaped. Make windows, doors and guttering because they do not rot or corrode. Making coloured objects such as toys as they are easily dyed. D. Mac an Aircinn Coláiste Chiaráin

Problems with Plastics Most are non-biodegradable When they burn they give off poisonous fumes. D. Mac an Aircinn Coláiste Chiaráin

Questions on Plastics Can you give the following Plastics (examples 5), Uses of plastics (5). properties of plastics (5) and how it affects their use (5) Problems of plastic for environment (2) D. Mac an Aircinn Coláiste Chiaráin