As the name suggests these elements are metals. Everything in this group (1) is an alkali metal and as such they share similar properties.

Groups 1

ALKALI METALS

They are very similar to normal metals, they are good conductors of electricity and when freshly just they are shiny.

However unlike most metals, their melting point is much lower. This means they melt with less heat.

The are soft, so we can cut it with a knife and they have a low density.

Apart from their physical properties, the main reason why alkali metals are so well know, is their chemical properties.

Group 1 elements are extremely reactive. This means, they easily take part in chemical reactions, with very little input.

All group 1 elements are extremely reactive with water. When the combine with the H2O molecules in water, they form Hydrogen gas.

This gas will push the element around the water, and you should see it moving.

The video to the left shows Cesium.  reacting with water

Sodium + Water                             Sodium Hydroxide + Hydrogen

  2Na(s)+ 2H2O(l)                                  2NaOH(aq)    +     H2(g)

Potassium + water                          Potassium Hydroxide + Hydrogen

    2K(s)    + 2H2O(l)                                  2KOH(aq)      +    H2(g)

So how can we test for these things?

When Lithium hydroxide is produced in water, it raises the pH level above 7 (neutral).

We can use a universal indicator to demonstrate this change. The potassium hydroxide forms an alkaline solution.

The large beaker contains tap water, While the smaller beaker contains water which recently reacted with Lithium. Watch the video on the right.
Notice how the colour in large beaker changes from Green to blue as the lithium hydroxide is added.

So, we know how to test for lithium hydroxide, but how do we test for hydrogen.

Hydrogen is a flammable gas, released by through this experiment. The video to the right shows a large amount of hydrogen escaping.

We can catch the hydrogen produced by the lithium in a balloon (to the left).

We can then ignite the balloon demonstrating that hydrogen was produced (to the right).