4.4 Elements in Group 1

• Name the first three names, symbol and electron arrangement for alkali metal 


  1. Lithium, Li, 2.1
  2. Sodium, Na, 2.8.1
  3. Potassium, K, 2.8.8.1
• List the physical properties of alkali metals

  • good conductor of electricity
  • shiny grey solid
  • low melting and boiling point among metals
  • has less density than water
  • soft and can be cut by a knife
• List the change in physical properties of alkali metal when going down group 1

  1. Size of atom increase
  2. Density increase
  3. Melting point decreases
  4. Metallic bond become weaker
• Why does the size of atom increase when going down group 1?

  because more and more shells are occupied with electrons
• Why does the density increase when going down group 1?

  mass increase faster than volume
• Why does the melting point decrease when going down group 1?

  when size of atom increase the metal bond become weaker
• Why do elements react with each other?

  To become stable
• What is the metabolic bond of force of attraction used for?

  for metal
• What is the vanderwaals/intermolecular force of force of attraction used for?

  non-metals
• List the change in reactivity of alkali metals when going down group 1

  1. Size of atom increases
  2. Valence electron is further away from the nucleus
  3. Force of attraction between nucleus and valence electron become weaker
  4. easier to donate electron
  5. more reactive
• the more easy it is to donate/release/lose 1 valence electron the more reactive.
• When moving down group 1, the valence electron moves further away from nucleus
• What happens when the valence elctron moves further away from nucelus?

  Force of attraction between nucleus and valence electron become weaker
• moving down goup 1 the more easier to donate electron
• moving down group 1 the more reactive
• Form the chemical formula forALkali + Water --> Alkali + Hydrogen Metal with:

  1. Na
  2. Li
  3. K

  2Na + 2H2O -> 2NaOH + H2

  2Li + 2H2O -> 2LiOH + H2

  2K + 2H2O -> 2KOH + H2
• What happens when these are put in water?

  1. Na
  2. Lithium
  3. Potassium

  Na = Dissolve quickly

  Lithium = Dissolve slowly

  Potassium = Dissolve very quickly
• Form the chemical formula: Alkali metal -> metal oxide + oxygen

  For these:

  1. Na (Sodium)
  2. Li (Lithium)
  3. K (Potassium)

  4Na + 2O2 -> 2Na2O

  4Li + 2O2 -> 2Li2O

  4K + 2O2 -> 2K2O
• Form the chemical formula Alkali metal + Chlorine gas -> metal chloride (white)With:

  1. Na
  2. Li
  3. K

  2Li + Cl -> 2Li Cl

  2Na + Cl -> 2Na Cl

  2K + Cl -> 2K Cl
• What happens when

  Na, Li, K

  is in a gas filled with oxygen

  1. Li burn slowly / dimly with red flame
  2. Na burn brightly with yellow flame
  3. K burn very brightly with purple flame
• What happens when Na, Li, K is in a gas filled with chlorine gas

  1. Li burn slowly / dimly with red flame
  2. Na burn brightly with yellow flame
  3. K burn very brightly with purple flame
• What are the safety precautions for Alkali Metals?

  1. Store in oil (paraffin oil)
  2. Put on gloves
  3. Use forceps