group 1

• ALKALI METALS:


  • Highly REACTIVE and are considered SOFT METALS with LOW DENSITY.
  • They all possess ONE ELECTRON in their OUTER SHELL, contributing to their reactivity and similar properties.
• Reactivity of Alkali Metals:

  • Reactivity INCREASES as you go down the group. Because the outer electron is easily lost due to the INCREASING DISTANCE from the nucleus and a WEAKER ATTRACTION.
  • They have LOWER MELTING AN BOILING POINTS and a HIGHER RELATIVE ATOMIC MASS as you move down the group.
  • When they react, group 1 elements tend to form IONIC COMPOUNDS with non-metals, usually resulting in white solids that dissolve in water to create colourless ALKALI solutions- hence the name ALKALI METALS.
• REACTION WITH WATER:

  • When reacted with water, alkali metals produce Hydrogen gas and react VIGOROUSLY.
  • The reactions become MORE VIOLENT reactions FURTHER DOWN the group.     
  • They also form HYDROXIDES that are alkaline when dissolved in water.
• REACTION WITH CHLORINE:

  • Group 1 metals react with Chlorine to form METAL CHLORIDES, which are WHITE SALTS.
  • The reactions become more VIGOROUS down the group.
• REACTION WITH OXYGEN:

  • The alkali metals react with Oxygen in the air forming METAL OXIDES, which is why the alkali metals TARNISH when exposed to the air.
  • The metal oxide produced is a dull coating which covers the surface of the metal.