Group 1: Atomic structure and the periodic table: Chemistry: GCSE (9:1)

• Name for Group 1 elements

  alkali metals

  
• Pattern in reactivity down group 1

  reactivity increases

  
• Density of group 1

  low density, which decreases down group 1
• Conductivity of group 1

  good conductors of heat and electricity

  
• Appearance of group 1 elements

  shiny when cut, but tarnish as they react with oxygen
• Colour of group 1 compounds

  White solids/colourless solutions

  
• Metal + water -->

  metal hydroxide + hydrogen
• Observations: Sodium + oxygen

  Burns with a yellow flame, producing a white solid

  
• Observations: Sodium + Water

  Floats on surface, melts into a bowl, fizzes, moves on the surface of the water
• Observations: Sodium + chlorine

  Burns with a yellow flame, producing a white compound
• Observations: Lithium + oxygen

  Burns with a crimson flame, producing a white compound

  
• Observations: Lithium + water

  Floats on the surface of the water, moves around and fizzes

  
• Observations: Potassium + water

  Floats on the surface of the water, moves around, fizzes, melts into a ball, burns with a lilac flame.

  
• Observations: Potassium + oxygen

  Burns with a lilac flame producing a white compound

  
• When group 1 elements react

  they lose their outer electron

  
• Potassium is more reactive than sodium because

  atomic radius increases, shielding increases, nuclear attraction decreases, easier to lose an electron