atomic structure & periodic table

• Properties of alkali metals:

  • Soft
  • Low density
  • Low melting point
  • Low boiling point
• Why are alkali metals to reactive?

  It's easier for them to lose 1 electron (+1 ion)
• Why does reactivity increase as you go down group 1?

  Increasing distance from nucleus and outermost shell weakens attractive force.
• Because alkalis are so reactive, they easily form what?

  Ionic compounds with non-metals
• Alkali + water ->

  metal hydroxide (alkaline) + H²(g)
• Observation when an alkali is put on water:

  It floats and fizzes
• Why are alkalis often stored in oil?

  To prevent hazardous reactions with the air
• Alkali + chlorine(g) ->

  white solids, which can dissolve in water to form a colourless solution
• Alkali + oxygen ->

  metal oxide (type depends on metal)
• When lithium reacts with oxygen:

  • burns
  • red flame
  • forms white solid
• when sodium reacts w/ oxygen:

  • strong orange flame
  • forms white solid
• when potassium reacts w/ oxygen:

  • Larger pieces: likac flame
  • Smaller pieces: make solid immediately
• when potassiun reacts w/ water:

  • ignites w sparks & lilac flame
  • disappears quickly