Alkalis, Halogens and Noble bases

• 3 Trends seen in group 1 metals as you go down the periodic table

  • Increased reactivity
  • Lower melting and boiling points
  • Higher atomic mass
• Reaction between a group 1 element and chlorine ?

  Ionic bond

  • Metal + Chlorine ~ Metal Chloride
• Properties of group 1 metals

  • Soft
  • Low density
  • Very reactive
  • Weak
  • Relatively low melting points (compared to other metals)
• Reaction between group 1 element and oxygen ?

  Oxidation

  • Metal + Oxygen ~ Metal Oxide
• Why do alkali metals become more reactive down the group ?

  Atomic size

  • Going down the group, atomic radius and shielding increase
  • Meaning there is a weaker electrostatic attraction between the outer-most electrons and the nucleus
  • Meaning amount of energy required to lose the outer-most electron decreases , making it easier for a reaction to occur.
• What are group 1 elements called ?

  Alkali metals.
• Reaction between a group 1 element and water ?

  Metal + Water ~ Metal Hydroxide + Hydrogen
• State and colour of bromine at room temperature ?


  Bromine is a red-brown liquid at room temp. .
• 3 Trends in the group 7 elements as you go down the periodic table

  • Decreased reactivity
  • Higher melting/boiling points
  • Higher atomic mass
• What type of bonds do Halogens form with metals ?

  Ionic bonds.
• Noble gases are 'inert' , what does 'inert' mean ?


  Non-reactive - don't react with other atoms
• Are noble gases metals or non-metals ?


  Non-metals
• Why do halogens become less reactive as you move down group 7 of the periodic table ?

  1. Atomic radius and shielding increase
  2. Means there is a weaker electrostatic attraction between the nucleus and the electron it is trying to gain
  3. Means more energy is required for a reaction to occur
• Are halogens metals or non metals ?


  Non-metals
• Are noble gases monoatomic or diatomic ?


  Monoatomic ; Exist as single atoms
• State and explain the trend in the boiling points of noble gases as you move down group 0 of the periodic table ?

  Boiling points increase as you move down due to the increase in atomic size and so can form more intermolecular forces, which will require more energy to overcome .
• What is the state and colour of chlorine at room temperature ?

  • A green colour
  • In the state of a gas
• What is a halogen displacement reaction ?

  A reaction where a more reactive halogen displaces a less reactive halogen from a compound.
• What is the physical state of group 0 at room temperature ?

  Gaseous
• Are halogens monoatomic or diatomic ?

  Diatomic ; exist in pairs of atoms
• What is the state and colour of iodine at room temperature ?

  • Dark grey solid ; gives off purple fumes
• Name the first 4 group 7 elements 


  • Fluorine
  • Chlorine
  • Bromine
  • Iodine
• What is the state and colour of fluorine at room temperature ?


  • A yellow colour
  • In the state of a gas
• What type of bonds do halogens form with metals ?

  Halogens form ionic bonds with metals
• Why are noble gases inert ?

  • Already have full outer-shell of electrons ; don't need to gain or lose electrons