The perdoic table

• Periodic trends

  1. Table moves from metals on the left to non-metals on the right.
  2. Down a group of metals, elements become more reactive
  3. With non-metals, going down a group, reactivity decreases
• Elements are arranged in order of increasing atomic number (each proceeding element has one more proton)
• Made up of rows called periods and columns called groups; the position of an element helps determine its electronic configuration
• Group number: number of valency electrons (outer shell electrons)
• Elements in the same group have similar chemical properties.
• Noble gas properties:

  • Density increases down the group
  • Monoatomic and colorless
  • M.P. and B.P. increases down the group
  • Don’t conduct electricity
  • Inert due to full outer shell electrons
• Noble Gases uses:

  • Helium- filling balloons and aircrafts because it is lighter than air and will not catch fire.
  • Argon – filling (tungsten) light bulbs to stop the filament reacting with oxygen.
  • Neon – is used in advertising signs because it glows red.
• Transation metals:

  • Transition metals have high melting points (except mercury)
  • Transition metals are malleable and ductile
  • Transition metals are good conductors of heat & electricity (silver is the best)
• Alkali metals:

  • Group I metals: Lithium, sodium and potassium
• Chemical properties of Alkali metals

  • Readily react with oxygen and water; stored in oil
  • React violently with chlorine
  • Burst into flames when heated with oxygen[red flame for lithium; yellow flame for sodium; lilac flame for potassium]
  • Produce soluble white compounds.
  • React with water to form alkaline metal and hydrogen gas
• Physical Properties of alkali metals

  • Good conductors of heat and electricity
  • Soft and easy to cut
  • Shiny when freshly cut
  • Low melting and boiling points compared to most metals
  • Low densities for metals