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| Questão | Responda |
| How many elements are there? | About 100 |
| What do the groups contain? | Elements with similar properties. |
| What is the symbol for sodium? | Na |
| What is in the nucleus of an atom? | Protons and Neutrons |
| What orbits the nucleus? | Electrons |
| what is the charge of an electron? | -1 |
| what is the overall charge of an atom? | zero |
| What does the atomic number tell us? | The number of protons. |
| What does the mass number tell us? | The sum of protons and neutrons. |
| Al has 13 electrons, give its electronic structure. | 2,8,3 |
| What is important about elements in the same group? | They have the same number of electrons in the outer shell. |
| What is the name for group 0 elements? | Noble gases |
| Why are group 0 elements unreactive? | Stable arrangement of electrons. |
| What 3 ways do atoms form compounds? | Giving, taking and sharing electrons. |
| What bonding is formed between a metal and non-metal? | ionic |
| What bonding is formed between non-metals only? | Covalent |
| What is important about the mass of a chemical reaction? | The mass stays the same. |
| What is the chemical name for limestone? | calcium carbonate CaCO3 |
| What is the name for the reaction where limestone is heated? | Thermal decomposition |
| What are the 2 products of heating limestone? | calcium oxide + carbon dioxide |
| Give 5 carbonates which also decompose. | Mg, Cu, Zn, Ca, Na |
| What is the product of reacting calcium oxide and water? | calcium hydroxide |
| What is calcium hydroxide used for? | neutralising acid |
| What is another name for calcium hydroxide? | Lime water |
| What do we get when we react calcium hydroxide with carbon dioxide? | calcium carbonate |
| What happens to lime water when you react it with carbon dioxide? | It goes cloudy |
| what forms when carbonates react with acid? | carbon dioxide, water and salt |
| How do we make cement? | Heat clay and limestone. |
| How do we make mortar? | cement and sand |
| How do we make concrete? | Cement, sand and aggregate. |
| What is an ore? | Rock that contains enough metal to make it economical to extract. |
| What happens to an ore? | Mined and concentrated, then extracted and purified. |
| Name a metal found in the Earth by itself? | Gold |
| How are most metals found? | As compounds |
| Which metals are extracted by reduction with carbon? | Metals lower than carbon in the reactivity series |
| How are more reactive metals extracted? | Electrolysis of molten compounds. |
| What is the disadvantage of electrolysis? | high cost |
| What is smelting? | Heating copper rich ores in a furnace. |
| What is the problem with copper ores? | Limited supply |
| Name 4 other ways of extracting copper. | Phytomining, bioleaching, displacement using scrap iron and electrolysis of copper salts. |
| Why is it expensive to extract Al and Ti? | Many stages in the process and large amounts of energy needed. |
| Why should we recycle metals? | Save resources, expensive in terms of energy, affects the environment. |
| How pure is iron from a blast furnace? | 96% |
| why is this impure iron almost useless? | impurities make it brittle. |
| What is steel? | An alloy of iron with carbon. |
| Give a property of low carbon steel. | Easily shaped. |
| Give a property of high carbon steel. | Hard |
| Give a property of stainless steel. | Resistant to corrosion. |
| Why do we usually make alloys from metals? | To make the harder for everyday use. |
| What do we call the elements in the central block of the periodic table? | Transition metals. |
| Give three properties of transition metals? | Conduct heat, conduct electricity, can be bent or hammered into shape. |
| What do we use copper for? | Electrical wiring and plumbing. |
| Why are Al and Ti useful? | Low density and resistant to corrosion. |
| What is crude oil? | A mixture of a large number of compounds that contain carbon and hydrogen. |
| What is a mixture? | Two or more elements or compounds that are not chemically combined. |
| What are hydrocarbons? | Compounds containing only carbon an hydrogen. |
| What are saturated compounds called? | Alkanes |
| What is the general formula for alkanes? | Cn H2n +2 |
| What process separates the compounds in crude oil? | Fractional distilation. |
| As the carbon chain increases, what happens to the boiling point? | increases |
| As the carbon chain increases what happens to the viscosity? | increases |
| As the carbon chain increases, what happens to the flammability? | Decreases. |
| What elements do most fuels contain? | Carbon, hydrogen and some sulphur. |
| What gases are produced when fuels are burnt? | carbon dioxide, water vapour, carbon monoxide, sulphur dioxide and nitrogen dioxide. |
| What happens to the carbon and hydrogen during combustion? | They are oxidised. |
| What is the main problem with sulphur dioxides and nitrogen dioxides? | Acidic rain. |
| What problem does carbon dioxide cause? | Global warming. |
| What problem do solid particles cause? | Global dimming. |
| From what do we make biofuels? | biodiesel and ethanol. |
| How do we get small hydrocarbons from larger ones? | Cracking |
| What is the process of cracking? | Heating the hydrocarbons to vaporise them, then passing over a hot catalyst or mixing with steam at a very high temperature. |
| What are the products of cracking? | alkanes and alkenes |
| What is the general formula for alkenes? | Cn H2n |
| What does = represent in an alkene? | A double bond. |
| What do we see when bromine water is added to alkanes? | The bromine water stays orange. |
| What do we see when bromine is added to alkenes? | The bromine goes from orange to colourless. |
| How are polymers made? | Many small molecules join together to form very large molecules. |
| What are the small molecules used to make polymers called? | Monomers |
| Give 2 uses of polymers. | Packaging materials, waterproof coating, dental polymers wound dressings, hydrogels, smart materials. |
| Why is the disposal of polymers a problem? | polymers are not biodegradable. |
| What are new biodegradable plastics made from? | Corn starch |
| Give 2 methods of making ethanol. | Reacting ethene with steam with a catalyst, or fermenting sugar with yeast. |
| Give the equation for fermentation. | yeast Sugar----> carbon + ethanol dioxide |
| From what are vegetable oils extracted? | Nuts, seeds and fruit. |
| How is the oil removed? | Plant material crushed, oil pressed out or distilled. |
| What is removed during the process? | Water and impurities |
| What are vegetable oils important for? | Food and fuel |
| Why are oils important? | They provide a lot of energy |
| Give an advantage of using oil to cook. | Food cooks faster, different flavour. |
| Give a disadvantage of using oil to cook. | More energy is released. |
| What is an emulsion? | mix of oil and water which doesn't separate. |
| Give 4 uses of emulsions. | Salad dressing, paints, cosmetics and ice cream. |
| What does hydrophilic mean? | likes water. |
| What does hydrophobic mean? | Dislikes water. |
| What do unsaturated molecules contain? | Double carbon=carbon bonds |
| What happens to bromine water with unsaturated molecules? | Turns from orange to colourless. |
| How do we harden vegetable oils? | Through hydrodgenation. |
| Describe the process of hydrogenation. | React vegetable oil with hydrogen, with a nickle catalyst at 60C |
| What is hardened vegetable oil? | Margarine |
| What are the three sections of the Earth? | Core, mantle, and crust. |
| What are the crust and upper mantle cracked into? | tectonic plates. |
| How fast do tectonic plates move? | A few cm per year. |
| What causes tectonic movement? | Radioactive decay causes convection currents. |
| What problems do plate movements cause? | Earthquakes and volcanoes. |
| What is the % of nitrogen in the atmosphere? | about 80% |
| What is the % of oxygen in the atmosphere? | 20% |
| Name 2 other gases in the atmosphere. | Carbon dioxide, water vapour, noble gases |
| What caused the gases in the early atmosphere? | Volcanoes |
| How were the oceans formed? | water vapour condensed |
| What gases were present in the early atmosphere? | Carbon dioxide, methane, ammonia, water vapour |
| What is the main theory as to how life was formed? | interaction between hydrocarbons, ammonia and lightning. |
| What produced the oxygen in the atmosphere? | Plants and algae |
| Where does carbon dioxide get removed from the atmosphere? | In sedimentary rocks as carbonates and fossil fuels. |
| What is the problem of carbon dioxide being absorbed into the ocean? | Impact on marine environment |
| What is causing the increase in carbon dioxide? | Burning fossil fuels. |
| How do we separate the gases in the air? | Fractional distillation. |
| Why can we separate the gases in the air? | They have different boiling points. |
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