Group 1

• Potassium, Lithium and Sodium all have similar reactions with water, increasing with reactivity as the group progresses
• They all show effervescence on the water, float and move on the surface, and eventually disappear
• A metal hydroxide solution is produced each time, with hydrogen
• The similarities provide evidence that Lithium, Sodium and Potassium are in Group 1, with one electron on their outer shells
• When reacting with oxygen, Group 1 metals show a similar trend in reactivity, providing evidence that reactivity increases as we go down the group
• it is possible to deduce the properties of francium from the trends in the other group 1 metals.

  we can predict that francium will have a melting point around 20⁰C and a density of just over 2g/cm³.

  We can also predict that francium will react violently with water, producing francium hydroxide and hydrogen.