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Atoms                                                       Group 1 Metals                                                     Group 7
What are atoms                                                 • They are known as alkali metals                                    Group 7 elements are known as halogens
      An atom has a nucleus in the centre and is              • Examples are _______________________                               Examples are ______________________
         surrounded by electrons.                           Reactions                                                          Physical properties
      The nucleus is positively charged                       • They are stored under oil because they react with air and          Chlorine is a green gas
      The electrons are negatively charged                         water.                                                          Bromine is an orange liquid
      The atom is neutral.                                    • They have _____ electron in their outer shell                      Iodine is a grey solid
      Nucleus is made up of protons and neutrons.             • Group 1 metals have similar properties because they have      Uses
      An atom is neutral because it has the same                   the same number of electrons in their outer shell               Chlorine – to sterilise water
         number of electrons and protons.                      • Alkali metals have similar properties because when they            Chlorine to make pesticides and plastics
Atomic Number                                                       react, an atom loses one electron to form a positive ion        Iodine is used to sterilise wounds (antiseptic)
      The Atomic number = Number of protons                        with a stable electronic structure                              Sodium chloride (salt) is used
Mass Number                                                          ionic equation –                                                       – As a preservative
      The Mass Number = number of protons +                   • They more reactive the alkali metal the easier it is for an                – As a flavouring
         neutrons.                                                  atom to lose one electron.                                              – To manufacture chlorine
Isotopes                                                       • This is known as oxidation.                                   Reactions
Isotopes are different forms of the same element with the   Reactions with Metals                                                   Group 7 elements have similar properties because
same number of protons but different number of neutrons        • Group 1 metals react vigorously with water.                           they have ____ electrons in their outer shell
Elements                                                       • Hydrogen is formed                                                 React vigorously with alkali metals to produce
      There are about 100 elements                            • An alkali is formed which is the hydroxide of the metal               metal halides
      It cannot be broken down chemically                     • Reactivity increases down the group                                Halogens have similar properties because when
      It contains the same type of atom                       • Word equation =                                                       they react, an atom gains one electron to form a
      They are arranged in ascending atomic number in         • Balanced equation =                                                   negative ion with a stable electronic structure
         the periodic table                                 Reactivity                                                              Write an equation to show the formation of a
Compound                                                       • Order of reactivity is:                                               halide ion from a halogen molecule
      A compound is a substance that contains at least                  1. Potassium                                               The more reactive the halogen the easier it is for
         two elements chemically combined                                2. Sodium                                                     the atom to gain one electron
Electronic configuration                                                 3. Lithium                                                     The gain of electrons is called reduction
      Electrons occupy shells around the nucleus.          Flame tests                                                        Reactivity - The order of reactivity is :
      Electronic configuration:                               • Lithium – Red                                                              – Fluorine
               Shell 1 – 2 electrons                          • Sodium – Yellow                                                            – Chlorine
               Shell 2 – 8 electrons                          • Potassium – Lilac                                                          – Bromine
               Shell 3 – 8 electrons                                                                                                       – Iodine
               Shell 4 – 8 electrons etc.                                                                                     Therefore reactivity decreases down the group
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Electrolysis                                                Metals                                                                Transition Elements
    • The anode is the positive electrode                       • Iron is used to make steel and to make cars and bridges
    • The cathode is the negative electrode                          because it is strong                                         Examples
    • Anions are negative attached to the anode                 • Copper is used to make brass and to make electrical wiring           Copper = Cu
    • Cations are positive ions attached to the cathode              because it is a good electrical conductor.                        Iron = Fe
    • An electrolyte is the liquid which conducts           Physical properties of metals                                              All transition elements are metals and have
         electricity                                            • Lustrous, hard and high density                                         typical metallic properties
Sulphuric acid solution                                         • High tensile strength                                           Colours
    • Sulphuric acid solution can be broken down by             • High melting & boiling point due to strong metallic bonds           • Compounds of transition elements are often
         electrolysis into hydrogen and oxygen                  • Good conductors of heat and electricity                                 coloured
    • Hydrogen (+ve) is made at the cathode (negative           • Particles in a metal are held together by metallic bonds                      – Copper compounds are blue
         electrode)                                         Properties                                                                          – Iron II compounds are light green
    • Oxygen (-ve) is made at the anode (positive               • Properties needed by a metal for a particular given use e.g.                  – Iron III compounds are orange/brown
         electrode)                                                  Saucepan bases need to be good conductors of heat            Catalysts
Test for gases                                              Crystals                                                                  • Transition elements and their compounds are
    • Test for hydrogen = burns with a ‘pop’ when lit           • Metals have a structure which contains crystals                         often catalysts
         using a lighted splint                                 • Particles in solid metals are close together and in a regular                 – Iron in the Haber process
    • Test for oxygen = relights a glowing splint                    arrangement                                                                – Nickel in the manufacture of margarine
Aluminium                                                       • At low temperatures some metals can be superconductors.                       – A catalyst _______ up the rate of a
    • Aluminium is extracted from its minerals using        Metallic bonding                                                                         reaction.
         electricity                                            • This can be described as strong electrostatic attraction                But it does not get used up.
    • Electrolysis is the decomposition of a liquid using            between a sea of delocalised electrons and close packed      Thermal Decomposition
         electricity                                                 positive metal ions                                              • This is a reaction in which a substance is broken
    • Bauxite is a mineral containing aluminium. It is          • This explains why metals have high melting and boiling                  down into at least two other substances by heat.
         molten aluminium oxide.                                     points – because of the strong attraction between the            • It usually results in a colour change
    • Oxygen is formed at the graphite anode                         delocalised electrons and the positive metal ions needs to   Precipitation
    • Anodes are gradually worn away by oxidation                    be overcome.                                                     • Reaction between solutions that makes an
    • Aluminium is formed at the graphite cathode           Electricity                                                                   insoluble solid
    • Process has a high electrical energy requirement          • When metals conduct electricity electrons move                      • Sodium hydroxide solution is used to identify the
    • Cryolite is used to lower the melting point of the        • These are delocalised electrons                                         presence of transition metal ions in solution:
         aluminium oxide                                    Superconductors                                                                     – Copper ion = blue solid
    • Aluminium is expensive because its extraction             • Materials that conduct electricity - little or no resistance                  – Iron II ion = green solid
         uses large amounts of electricity                      • They can be powerful electromagnets                                           – Iron III ion = orange solid
                                                                • However they only work at very low temperatures                 These are all solid precipitates
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