Group 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 + 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