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Chemistry 1a Speaking and Listening test Atomic Structure and Fundamental Ideas 1. 2. 3. 4. 5. 6. 7. 8. 9. What is an element? A substance made up of only 1 type of atom. What is a compound? 2 or more elements chemically joined together. What are the names of the 3 subatomic particles? Proton, Electron and Neutron What 2 particles are located in the nucleus? Protons and Neutrons Where are the electrons found? In shells/energy levels around the nucleus. What charge does a proton have? Positive What Charge does a neutron have? No charge/ neutral What charge does an electron have? Negative Why are elements said to have no overall charge? They have equal numbers of protons and electrons. The charges cancel out. 10. What is the mass (how heavy) of each subatomic particle Proton =1 Neutron=1 Electron = 0 11. What is the atomic number? The number of protons (the bottom number). It is also the number of electrons. 12. What is the mass Number? The number of protons and the number of neurons added together (the top number) 13. What is an isotope? An atom of the same element with different numbers of neutrons. 14. How are the electrons arranged in shells around the nucleus? 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 1st shell hold up to 2 2nd shell holds up to 8 3rd shell holds up to 8 4th shell holds up to 18 How does the electronic configuration identify where elements are found in the periodic table. The group number is the same as the number of electrons in the outermost shell. Eg all elements in group 1 have 1 electron in their outer shell. Elements in the same group have similar what? Chemical properties. They all behave in a similar way. What are the elements in group 0 known as? The noble gases Why are they unreactive? They have a full outer shell. Why do elements bond together to form compounds? To gain a full outer shell by swapping (ionic) or sharing (covalent) ELECTRONS What types of elements form ionic compounds? Metals and Non-metals What type of elements form covalent compounds? Non-metals How can we represent chemical reactions? Balanced symbol and word equations. What are the reactants? What is put into a chemical reaction? What are the products? What is produced in a chemical reaction What can we say about the mass of the reactants and products? It is the same before and after the reaction. (Conserved) Limestone and Building Materials 1. 2. 3. 4. 5. 6. 7. 8. 9. What type of rock is Limestone? Sedimentary rock What is it made from? Remains of crushed sea shells What is its chemical name and formula? Calcium Carbonate CaC03 What happens when we heat it? It breaks down into Calcium Oxide and Carbon Dioxide. What type of reaction is this? Thermal Decomposition What is formed when Calcium oxide is added to water? Calcium Hydroxide What happens when we put carbon dioxide into the Calcium Hydroxide. It reforms Calcium Carbonate What is another name for a solution of Calcium Hydroxide? Limewater What gas does limewater test for? Carbon Dioxide 10. What is produced when a metal carbonate reacts with an acid? Metal Salt + Carbon Dioxide and Water 11. How is cement made Heating with clay in a rotary kiln 12. How is concrete made Mixing cement with sand water and crushed rock 13. What is another word for small stones or gravel added to cement to make concrete. Aggregate 14. What are the advantages of quarrying limestone? More employment for local people More customers and trade for local businesses Improved roads 15. What are the disadvantages of quarrying limestone? Dust and Noise Traffic Loss of habitats for wildlife. Metals and their uses- The reactivity series is given in the exam. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. Where will you find metals on the periodic table? On the left hand side. List 5 properties of metals. Conduct Heat Conduct Electricity Most are solids at room temperature. Can be bent into shape-malleable Can be pulled into wires-ductile Where do we get the metals that we use? The Earths crust How do we get the metals? Mining or quarrying What is an environmental impact of quarrying? Damage to the habitats of animals Production of pollutant gases by plant traffic. What is an economic impact of quarrying? Provides jobs for the local community What is a social impact of quarrying? Jobs-positive How is the metal is usually found in the earth’s crust? In the form of an ORE What is an ORE? A rock that contains enough metal to make it worth extracting. The method of extracting the metal depends on what? The reactivity of the metal. Name 3 metals that are found in the earth’s crust as the metal themselves. Gold Silver Platinum How do we extract metals from their ores that are less reactive than carbon? Heat them with carbon. How are metals that are more reactive than carbon extracted? Electrolysis What is electrolysis? Passing an electric current through the molten ORE What metals are extracted by electrolysis. Aluminium and Titanium Why is this process expensive? Many steps in the process Lots of energy used. Why is copper used for? Used in water pipes Construction Electrical cables Name three ways in which copper is extracted? Heating with carbon (smelting) then purification by electrolysis Phytomining Bioloeaching 19. What are the steps involved in phytomining? Grow plants on areas of low grade ore. Plants absorb the copper ions Burn the plants React the ash with Sulphuric acid to form copper sulphate Purify the copper by electrolysis 20. What is Bioleaching? 21. Why are we now extracting copper from low grade ores? Copper is in such high demand We are running out of higher grade ores The new techniques have been developed 22. Why can iron be used to displace copper from solutions containing copper? It is more reactive 23. Why are pure metals soft? It contains atoms that are all of the same size They can easily roll over one another. 24. What is an alloy? A mixture of a metal with other elements (usually metal) 25. What is the benefit of an alloy? Stronger Resistant to corrosion 26. What is the name of the alloy of Iron? Steel 27. What are the key properties of aluminium and titanium that make them useful for aircraft? Both have low density (light) Both have very high melting points. 28. Where are the transition metals located? In the central block of the periodic table Changes in the earth and its atmosphere 1. 2. 3. Name the parts of the earth? Core Inner/Outer Mantle Crust Alfred Wegener put forward the idea of continental drift and that the continents existed as one super continent. What evidence did he have? Shape of the continents look like they could fit together like a jigsaw puzzle Fossils from different continents matched up. Why were his ideas not accepted? Not enough evidence The believed the earth was shrinking as it cooled. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. What are the names of the plates making up the earth’s crust? Tectonic plates What causes them to move? Convection currents in the mantle What causes the convection currents? Radioactive processes in the core cause the mantle to heat up causing the convection currents. Why can scientists not predict where and when earthquakes occur? The changes occur inside the earth’s mantle which scientists cannot measure. What was the composition of the early atmosphere? Mainly Carbon Dioxide, water vapour methane and ammonia. What is believed to have produced these gases? Volcanic Activity What is the composition of the earth’s atmosphere today? 79% Nitrogen 20% Oxygen 1% Carbon Dioxide and other gases. What caused the change in atmosphere? The evolution of algae and green plants resulted in photosynthesis where Carbon Dioxide is used up and Oxygen is produced What processes led to the reduction of carbon dioxide in the atmosphere over time. Photosynthesis Dissolves in the ocean and is incorporated into shells and sedimentary rocks Locked up in living organisms What processes produce carbon dioxide Burning of fossil fuels Respiration Decay What can increasing levels of carbon dioxide in the atmosphere result in? Global warming Higher Tier Only Theories on how life on earth began. 1. 2. 3. What was the Miller Urey Experiment? An experiment where the mixture of gases believed to be present in the early atmosphere were mixed together and given a high voltage spark to simulate lightning What did they find? They found that they could produce the building blocks of life know as amino acids Why was this not definite proof of how life began? They only produced building blocks of life not any living thing They have no definite evidence of the composition of the gases in the early atmosphere. Separating gases in the air 4. 5. How can gases be separated in the air? Fractional distillation How is it done? Air is cooled to below -200C Carbon Dioxide and Water freeze and are removed It is passed into a column with a temperature gradient. Oxygen is collected as a liquid Nitrogen passes out the top as a gas