C3 Revision

  1. Before 1800, how were elements were classified?
    • 1) Their physical and chemical properties.
    • 2) Their relative atomic mass.
  2. Why did Mendeleev leave gaps in his Table of Elements?
    To keep elements with similar properties in the same vertical columns also to leave room for elements that haven't being discovered yet.
  3. Describe the density of the alkali metals.
    The alkali metals have low melting and boiling points compared to most other metals. Apart from the otheralkali metals, only three metals (indium, gallium and mercury) have lower melting points than lithium. You can see from the graph that lithium, at the top of Group 1, has the highest melting point in the group.
  4. Describe the physical properties of a typical transition metal.
    • they form coloured compounds
    • they are good conductors of heat and electricity
    • they can be hammered or bent into shape easily
    • they are less reactive than alkali metals such as sodium
    • they have high melting points - but mercury is a liquid at room temperature
    • they are usually hard and tough
    • they have high densities
  5. Give two uses of alcohols?
    • Drinks
    • Industrial methylated spirits (meths)
  6. Give an advantage of using hydrogen as a fuel in a car engine?
    • unlike petrol and diesel, hydrogen does not generate carbon dioxide when burnt
    • hydrogen fuel cells are very efficient
  7. Describe two ways of testing for metal ions.
    • The flame test: Red Lithium, Li+.Orange Sodium, Na+. Lilac Potassium , K+. Brick red Calcium, Ca2+
    • Using white precipitates
  8. What is a fuel cell?
    A cell producing an electric current direct from a chemical reaction.
  9. Is energy released when bonds are formed or when bonds are broken?
    Is energy released when bonds are formed or when bonds are broken?
  10. What is shielding?
    Shielding effect can be defined as a reduction in the effective nuclear charge and the electronic cloud,due to difference in the attraction forces of the electrons on the nucleus. It is also refereed as the screening effect or atomic shielding.
  11. Give two uses of carboxylic acids? 
    • Vinegar 
    • Soap
  12. Name a suitable indicator you could use in the titration of sulfuric acid and sodium hydroxide?    
    Hydrochloric acid.
Card Set
C3 Revision
C3 revision for GCSE