C1.1

C1.1

1. 1. Atoms and Elements

   • Elements
     • A substance that contains only one type of atom
   • Atoms
     • An atom is the smallest particle of an element. Their nucleus contains, protons and neutrons. And the whole atom is orbited by electrons
   • All elements can be found in the periodic table

2. 2. Inside atoms

   • Nucleus
     • Protons
     • Neutrons
   • Outside nucleus
     • Electrons
       • Maximum of 8 per shell
   • Particle charge
     • Proton = +1
     • Neutron = 0
     • Electron = -1

3. 3. Inside compounds

   • Compounds are made up of two or more elements chemically bonded together
   • Ionic bonds
     • When a metal reacts with a non-metal
     • Electrons transfer from one shell to another
       • To gain a full outer shell of 8 electrons

4. 4. Chemical reactions

   • Reactants
   • Products
   • Word equations
     • e.g. Sodium+Chlorine --> Sodium Chloride
   • Formulae
     • Tells us the number and type of atoms are joined afterthe reactions

5. 5. Chemical equations

   • Symbol equations
     • Must be balanced
     • e.g. for burning titanium
       • Ti + O2 --> TiO2
   • Atoms cannot be made or lost in chemical reactions

6. 6. Limestone

   • Attractive, durable & strong
   • Acid rain
     • Calcium carbonate + sulfuric acid --> Calcium sulfate + Carbon dioxide +water
     • CaCO3 + H2SO4 --> CaSO4 + CO2 + H2O
     • Sulfur dioxide
   • CaCO3
   • Quarrying
     • Benefits
       • Jobs
       • Valuable products
         • National income
     • Problems
       • Traffic (transport of material)
       • Takes up land
         • Picturesque villages / towns

7. 7. The Lime Cycle

   • Calcium oxide
     • CaCO3(s) --> CaO(s) + CO2(g)
   • Thermal decomposition
     • When limestone is heated the mass decreases because carbon has been released as a gas which carries some of the mass
   • Making Calcium Hydroxide
     • CaO(s) + H2O(l) --> Ca(OH)2 (s)
   • Calcium oxide and Calcium hydroxide
     • Both are alkaline solutions with water
     • Uses include;
       • Neutralising excess acidity in lakes and soils
       • Neutralising acidic waste gases from coal power stations

8. 8. Products from limestone

   • Cement
     • Powdered clay is added to crushed limestone and heated to 1450C, then add calcium sulfate powder
   • Mortar
     • Used to secure bricks
   • Concrete
     • Cement, sand and small stones
   • Thermal decomposition
     • e.g. CuCO3(s) --> CuO(s) + CO2(g)

9. 9. Magnificent Metals

   • Transition metals are located in the middle of the periodic table
   • Ores
     • Ores are put into blast furnaces with a more reactive substance and heated
       • Reactivity series
       • Leaves ore and releases waste material
       • e.g. tin oxide + carbon --> tin + carbon dioxide

10. 10. Steel

    • From blast furnace 96% iron and 3% carbon and impurities
    • Cast iron
      • Re--melting and adding scrap steel
    • Pure iron removes impurities from the blast furnace
    • Alloy
      • Steel = iron, carbon and sometimes other metals
      • Steel is harder and less bendy than pure iron because of atom arrangement
    • Low carbon steels are malleable and used from car body panels and food cans
    • Stainless steel
      • Does not go rusty because they contain chromium atoms
      • Cutlery, surgical instruments, kitchen appliances