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 + 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 + 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.
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