1. C3d Group 1 - The Alkali Metals
Flame Tests
You need to be able to describe how to carry out a flame test to test for the
presence of lithium, sodium and potassium compounds:
1.
2.
3.
Results
Element Colour
Lithium, Li
Learn
Sodium, Na
Potassium, K

2. C3d Group 1 - The Alkali Metals
In the table is some information about lithium sodium and potassium. Use this
information to predict the properties of Rubidium, Caesium and Francium:
Name Appearance Flame Colour Denisty Melting Boiling point
(used in fireworks ! ) gcm-3 point ( 0C )
( 0C )
Lithium Shiny, soft, silver- red 0.53 181 1342
Li grey
Sodium Shiny, soft, silver- yellow 0.97 98 883
Na grey
Potassium Shiny, soft, silver- lilac 0.86 63 760
K grey
Rubidium Soft, silvery-white red
Rb
Caesium Cs Soft, shiny, gold- blue
coloured,
Francium Not available in visible unknown
Fr quantities
Trends (patterns):
• Group 1 metals are all _______
• They are generally ___________ and ____________ in colour
• Their density generally ________________ as you go down the group.
The first __ have a lower density than water (1.0gcm-3) so they _________ on it.
• All of group 1 are very _____________ metals.
They can be easily cut with a knife. They get ________________ as you go down
the group.
Why are they called the Alkali Metals?

3. For this we have to look at their reactivity with water. Watch the demonstration and
then fill in the sheet.
Alkali Observations (What did you see happening) Colour of universal
metal indicator
Li • floats
• fizzes __________, disappears __________
• moves _______ around the surface (as a cube)
Na • floats
• fizzes __________, disappears __________
• melts to form a ball
• moves _____________ over the surface
K • floats
• fizzes and disappears _________________
• ________ to form a ball
• moves ________________ over the surface
• burns with a ____________ flame
LEARN • The gas produced is ______________.
• Test for hydrogen: a _________________
• We can see from the colour of the universal indicator (blue/purple) that an
Result: it burns with a
“_______________”
alkaline solution is produced when the alkali metals are reacted with water.
This is why Group 1 is called the Alkali Metals.

4. • The alkali metals react __________________ with water so they are stored
under ______ to stop them reacting with _______ and ________________.
• the reactivity with water increases down Group 1
• an alkali is formed which is the hydroxide of the metal
What reaction is taking place?
lithium + water lithium hydroxide + hydrogen
sodium + water +
potassium + water +
Predict how rubidium would react with water, in terms of what you would observe
happening and the products that would be made. Write equations.
Notice that all the equations are balanced in exactly the same way, it’s only the symbol
of the metal that changes. This means that you only need to learn 1 word and 1 symbol
equation !! all of group 1 react with water in this way?
Why do
• All of the Group 1 metals have _______ electron in the outer shell.

5. • All of them want to react and ____ that one electron because this leaves them
with a full shell underneath which is a more ___________ electronic structure
to have.
• It is relatively easy to lose just one electron so they are all very __________
metals.
• The more reactive the alkali metal, the easier it is for an atom to lose one
electron and form a ________________ ion.
Oxidation (and reduction)
When an atom loses an electron it becomes a positive ion. We can show this in a
special type of equation called an “_______________________”
e.g.
• When an atom or ion loses electrons we is has been __________________ or
that is it an oxidation reaction.
• If an atom or ion gains electrons we say it has been ____________________ or
it is a reduction reaction
OIL RIG
Oxidation Is Loss of electrons
Reduction Is Gain of electrons
Task:
Write equations to show how sodium and potassium form ions
Sodium:
Potassium: