C5 0.0 / 5 ? ScienceChemicals of the natural environmentGCSEOCR Created by: zoeCreated on: 16-03-14 08:44 What is the atmosphere? a layer of gas surrounding the earth 1 of 35 What is the atmosphere made up of? the elements nitrogen, oxygen and argon, the compounds, carbon dioxide and water vapour 2 of 35 What is the hydrosphere mostly made up of? water and some dissolved compounds 3 of 35 What is the lithosphere? the rigid outer layer of the earth made up of the crust and the part of the mantle just below it 4 of 35 What does the lithosphere consist of? a mixture of minerals like silicon dioxide and an abundance of the elements silicon, oxygen and aluminium 5 of 35 What is the dry atmospheric air made up of? 78% nitrogen, 21% oxygen, 1% argon, 0.04% carbon dioxide 6 of 35 What do the chemicals that make up the atmosphere consist of? non-metal elements, molecular compounds made up from non-metal elements 7 of 35 Apart from water what state are the molecules that make up the atmosphere at 20*c? gasses 8 of 35 Why dont pure molecular compounds conduct electricity? their molecules arent charged 9 of 35 What happens to the electrons in a covalent bond? shared between the atoms 10 of 35 In a covalent bond what is created between each positive nucleus and the shared pair of negative electrons? strong electrostatic attraction 11 of 35 What two things are both minerals formed from pure carbon that is found in the lithosphere? diamond, graphite 12 of 35 Why is graphite soft? the covalent bonds are arranged in sheets that can easily slide over each other 13 of 35 Why can graphite conduct electricity? spare electrons can move between the layers of atoms 14 of 35 Why is diamond so hard? each atom is covalently bonded to 4 other atoms 15 of 35 What are the properties of silicon dioxide? hard, high melting point, electrical insulator, insoluble in water 16 of 35 Why is seawater in the hydrosphere salty? it contains dissolved ionic compounds called salts 17 of 35 Why do ionic compounds have high melting points? the ions are held together by strong forces of attraction in a lattice 18 of 35 Why don't solid ionic compounds conduct electricity? the ions are fixed in place and cant move 19 of 35 Why cant molten (or dissolved) ionic compounds conduct electricity? the ions aren't free to move 20 of 35 What can you use to detect ions in aqueous solutions? precipitation reactions 21 of 35 What is formed when calcium and carbonate ions are combined? form the insoluble ionic compound calcium carbonate or limestone 22 of 35 How can many positive metal ions be identified in a solution? adding sodium hydroxide and observing the precipitate colour 23 of 35 How can many negative ions be identified in solution? they will react with other aqueous ions to produce an insoluble precipitate 24 of 35 What are ores? rocks that contain varying amounts of minerals, from which metals can be extracted 25 of 35 How can metals that are less reactive than carbon be extracted from their oxides? heating it with carbon as the metal oxide is reduced and the carbon is oxidised 26 of 35 What is the total mass of the atoms in a compound called? relative formula mass 27 of 35 What is electrolysis? the breaking down of an electrolyte using an electric current 28 of 35 When is electrolysis used? to extract reactive metals from their ores because they're too reactive to be extracted by heating with carbon 29 of 35 What happens to the ions when they get to the oppositely charged electrode in electrolysis? they're discharged 30 of 35 What happens when a direct current is passed through a molten ionic compound? positively charged ions are attracted to the negative electrode, negatively charged ions are attracted to the positive electrode 31 of 35 What does malleable mean? metals can be beaten into shape or dented as the layers of metal ions can slide over each other 32 of 35 What is the environmental impact of mining? wasted rock, leaves a scar on the landscape, air/noise pollution 33 of 35 What is the environmental impact of processing? transport pollution, energy usage, electrolysis uses more energy than redction 34 of 35 What do the properties of metals determine? What they are used for 35 of 35
Comments
No comments have yet been made