Chemistry Y8 C2

• Periodic Table


  Contains elements

  
• Element symbol


  Either 1 or 2 letters
• Capitalization rule for element symbol


  First letter is capital, second letter is lowercase
• Groups in the Periodic Table


  • Metals (left side)
  • Non-metals (including hydrogen, right side)

  
• Metalloids


  Elements with some properties of both metals and non-metals
• Mercury (Hg) and Bromine (Br) are the only two elements that are liquid at room temperature
• Except for mercury, all metals are solids at room temperature
• Except for bromine, all non-metals are either solids or gases at room temperature
• Physical properties


  Observed or measured
• Chemical properties


  How something reacts
• Brittle


  Shatters easily
• Conductor


  Material that transfers electrical or heat energy well
• Density


  Mass of a material in a certain volume
• Ductile


  Able to be pulled into wires
• Malleable


  Able to be hammered into different shapes
• Sonorous


  Makes a ringing sound like a bell when hit
• Physical properties of metals


  • Electrical conductor
  • Heat conductor
  • High density
  • Shiny
  • Ductile
  • Malleable
  • Not brittle
  • Sonorous
  • High melting point
• Physical properties of non-metals


  • Poor electrical conductor
  • Poor heat conductor
  • Low density
  • Dull
  • Not ductile
  • Not malleable
  • Brittle
  • Not sonorous
  • Low melting point
• Reaction of metals and non-metals with oxygen


  Reactant + oxygen → product (oxide)
• Most metal oxides are solids at room temperature and when they dissolve in water, they make alkaline solutions
• Most non-metal oxides are gases at room temperature and when they dissolve in water, they make acidic solutions
• When fuels burn, nitrogen dioxide and sulfur dioxide can form, and if they dissolve in water in the air, they form acid rain
• Period


  Row on the periodic table
• Group


  Column on the periodic table
• The periodic table has trends in properties going across a period and up/down a group

  
• Periodic trends

  • Melting point
  • Boiling point
  • Density
  • Reactivity
• Alkali metals


  Group 1 metals
• Hydrogen is not a metal
• Alkali metals


  • Lithium
  • Sodium
  • Potassium
  • Rubidium
  • Caesium
  • Francium
• Properties of alkali metals compared to most metals


  • Lower density
  • Lower melting and boiling points
• Going down the group from lithium to caesium

  Melting and boiling points decrease, reactivity increases
• Reaction of alkali metals with water


  Alkali metal + water → hydrogen gas + alkaline solution
• Halogens


  Group 7 elements
• Halogens


  • Fluorine
  • Chlorine
  • Bromine
  • Iodine
  • Astatine
• Halogens are non-metals with low melting and boiling points, and do not conduct electricity
• Going down the group from fluorine to iodine


  Melting and boiling points increase, colours get darker
• Going down the group from fluorine to iodine


  Reactivity decreases
• Displacement reaction


  A more reactive element displaces (or pushes out) a less reactive element in a compound
• If element X is more reactive than element Z, the products are compound XY and element Z
• If element G is less reactive than element J, there is no reaction