Chemistry C1

Chemistry C1

Fundamental Ideas
1. Atoms Elements and Compounds
  1. All substances are made from atoms
  2. Element- Made from one type on atom
  3. Chemical symbols represent atoms
  4. Compound- Made from more than one element
2. Atomic Structure
  1. Nucleus made up of protons and neutrons
  2. Charge
    1. Protons- Positive Neutrons- Neutral Electrons- Negative
    2. Atoms have overall chrrge of 0
  3. Atomic number is equal to the number of protons
    1. Elements arranged on periodic table in order of proton number
  4. Mass number is sum of protons and neutrons
    1. So, Mass Number - Atomic Number = Number of Neutrons
3. Arrangement of Electrons in Atoms
  1. Noble gases (Group 0) are very stable so are unreactive
  2. Electrons are arragned in shells around the nucleus
    1. Shell one holds 2 electrons, after that they hold 8
    2. Shell one is closest to the nucleus
    3. Electrons fill from shell one first
  3. Elements in the same group have same number of electrons in their outer shell
4. Forming Bonds
  1. Metals bond with non metals ionically
    1. Ion- Charged particle
  2. Formula of ionic compouds shows the ratio of ions
  3. Non metals bond covalently to form molecules
  4. Formula of a molecule shows that atoms in the molecule
5. Chemical Equations
  1. During reactions, atoms get rearraged, but never created distroyed or changed
  2. Mass of Reactants = Mass of Products
  3. Word equations state the name of reactants and proucts, where as symbol equations give formulas
    1. Symbol equations should always be balanced
Rocks and Building Materials
1. Limestone and its Uses
  1. Limestone is Calcium Carbonate (CaCO₃)
  2. Uses
    1. Building material
    2. To make calcium oxide
    3. Cement
    4. Concrete
      1. Cement, aggregate, sand and water
  3. Limestone decomposes when heated
    1. Thermal Decomposition
2. Reactions of Carbonates
  1. Metal carbonates decompose when heated to produce the metals oxide and carbon dioxide
  2. Carbonate + Acid = Salt + Water + Carbon Dioxide
  3. Carbon Dioxide turns Calcium Hydroxide (Lime Water) cloudy, by forming insoluble calcium carbonate
3. Limestone Reaction Cycle
  1. 1. Thermal decomposition of calcium carbonate to form calcium oxide and carbon dioxide
    1. CaCO₃ -> CaO + CO₂
  2. 2. Hydration of calcium oxide to form calcium hydroxide
    1. CaO + H₂O -> Ca(OH)₂
    2. Calcium hydroxide is an alkali used to neutralise acids such as acidic soil
  3. 3. Dissolving of calcium hydroxide to form calcium hydroxide solution
    1. Ca(OH)₂ + H₂O -> Ca(OH)₂ (aq)
  4. 4. Carbon dioxide added to form calcium carbonate precipitate
    1. Ca(OH)₂ + CO₂ -> CaCO₃ + H₂O
4. Cement and Concrete
  1. Cement is made by heating clay and limestone in a kiln
    1. Product is then ground to a powder
  2. Mortar is made by mixing cement sand and water
  3. Concrete is made by mixing aggregate (small stones) into mortar
5. Limestone Issues
  1. Quarrying and processing Limestone
    1. Advantages
      1. More employment and local job oppurtunities
      2. Improved roads
      3. Increased trade
    2. Disadvantages
      1. Dust and noise
      2. More traffic
      3. Loss of habitat
Metals and their Uses
1. Extracting Metals
  1. Metals are usually found in the Earth's crust, often as compounds with other elements such as oxygen
  2. Ore- Metal compound containing enough metal to make extracting it worth while
  3. Unreactive metals are found in the Earth as the metal
  4. Metal oxides, where the metal is less reactive than carbon, can be reduced using carbon
2. Irons and Steels
  1. Iron oxides can be reduced in a blast furnace to produce iron
  2. Blast furnace iron is too brittle to use
  3. Most iron is converted into an alloy, steel
  4. Steel contains calculated quantities of carbon and other elements
3. Aluminium and Titanium
  1. Resist corrosion
  2. Lower densities than other strong metals
  3. Have to be extracted by electrolysis
  4. Extraction is expensive due to the large amounts of energy needed
4. Extracting Copper
  1. Most copper is extracted from ores by smelting
  2. Copper is then purified by electrolysis
  3. Copper rich ores are a limited resource so scientists are find new ways of sourcing copper
  4. Phytomining- Using plants to absorb copper compounds, which are collected from the plant's ashes
  5. Bioleaching- Uses bacteria to produce copper compound solutions
  6. Copper can be extracted from solutions by displacement or electrolysis
5. Useful Metals
  1. Central block of periodic table are the transition metals
  2. Transition metals have useful properties such as being strong yet malleable
  3. Most metals we use are alloys
6. Metallic Issues
  1. Recycling saves energy and limited resources
  2. Using metals in construction
    1. Disadvantages
      1. Uses limited resources
      2. Can rust
      3. More expensive than other materials
    2. Advantages
      1. Strong
      2. Malleable
      3. Ductile
      4. Good conductors of heat and electricity
Crude Oils and Fuels
1. Fuels from Crude Oil
  1. Crude oil is a mixture of many compounds
  2. Distillation separates a mixture of liquids
  3. Most of the compounds in crude oil are hydrocarbons- only contain hydrogen and carbon
  4. Alkanes are saturated hydrocarbons, meaning there are as many hydrogen atoms as possible in the molecule
2. Fractional Distillation
  1. Crude oil can be separated into fractions by fractional distillation
  2. Properties of these fractions depend on molecule size
  3. Fractions with lower boiling points are less viscous and more flammable
3. Burning Fuels
  1. Burning hydrocarbons produces carbon dioxide and water
  2. Burning hydrocarbons in a limited air supply causes incomplete combustion and may produce carbon monoxide and soot
  3. When burnt sulphur compounds produce sulphur dioxide and nitrogen compounds form nitrogen oxides
    1. Both can cause acid rain
4. Cleaner Fuels
5. Alternative Fuels
Products from Oil
1. Cracking Hydrocarbons
2. Making Polymers from Alkenes
3. New and Useful Polymers
4. Plastic Waste
5. Ethanol
Plant Oils
1. Extracting Vegetable Oil
2. Cooking with Vegetable Oil
3. Everyday Emulsions
4. Food Issues
Our Changing Planet
1. Structure of the Earth
2. Restless Earth
3. Earth's Atmosphere in the Past
4. Life on Earth
5. Gases in the Atmosphere
6. Carbon Dioxide in the Atmosphere

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	Criado por Phoebe Drew mais de 9 anos atrás