Group 1 - Alkali metals

• Lithium - Li

  Sodium - Na

  Potassium - K

  Rubidium - Rb

  Caesium - Cs

  Francium - Fr

  low density
• Properties:

  • silvery solids - stored in oil
  • 1 electron in outer shells - very reactive
  • Low density - soft - can be cut with knife
• Trends:

  • Reactivity increases down group - alkali metals react by losing single electron - as you move down the group, outer electron gets further away from nucleus - attraction between outer electron and nucleus decreases so outer electron is more easily lost
  • Melting / boiling points decrease down the group
  • Relative atomic mass increases down the group
• Relative atomic mass = protons + neutrons
• Atomic number = number of protons
• Alkali metals react with non-metals to form


  ionic compounds (1 +)
• Alkali metal + water


  Metal hydroxide + hydrogen

  ( sodium +water goes to sodium hydroxide + hydrogen)
• Alkali metal + chlorine 


  metal chloride

  ( lithium + chlorine goes to metal chloride)
• Alkali metal + oxygen


  metal oxide

  ( potassium + oxygen goes to potassium oxide)