9
!You should only do this practical exercise when under the supervision of a teacher

Pages

1Where is Mars?2How long will it take to get to Mars?3Getting to Mars4How do rockets get off the ground?5Producing Thrust6What happens when rocket fuel burns?7Your mission to Mars!8Our need for oxygen9How oxygen gets to our cells10The effects of gravity11How low gravity affects bones12Preventing bones and muscles from becoming weak13Living and working in space14What do astronomers know about Mars?15A space-craft view of Mars16Exploring Mars17Energy for exploration18The rocky surface of Mars19More about the surface of Mars20The Martian atmosphere21The importance of water22The water cycle on Earth23Is there water on Mars?24Surviving on Mars25Your Martian home26Farming on Mars27Soil on Mars28Plants for Mars29Getting energy on Mars30Where will you go next?

Practicals

1Modelling the solar system in the school yard2Rocket Practical3Investigate the Energy in Fuels4Making a Telescope5What factors affect the output of a solar cell?6Modelling Diffusion7Examining Slides of Blood8What bones are like without calcium salts9Flame Test to Identify Metals10The Different States of Water11Water Purification for Human Consumption12Factors Affecting Germination13Solar Cells for Devices14Mars Bingo
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Practical 9

Flame Test to Identify Metals

This practical helps us to identify the metallic elements present in a range of samples. The samples used here are solutions of metallic compounds. These compounds can often be found within rocks and minerals and give them particular colours.

Safety

These safety points mainly tell you about hazard. You will need to think about the risk(s) this might pose, and how you can minimize the risk.

Apparatus and Materials

The following solutions each in a 250 cm3 conical flask, labelled A-F:

Also:

Method

  1. Put a dry spill into each of the metal salt solutions in conical flasks and leave.
  2. Use a dry spill to light the Bunsen. 
  3. Take one of the spills from one of the conical flasks containing a metal salt solution.
  4. Wave your spill over the Bunsen flame and observe its colour. Then extinguish the used spill and dispose of it. 
  5. Record the metal salt solution and the flame colour.
  6. Repeat steps 2 to 4 for each of the other metal salt solutions you have been provided with.

Results Table

Sample Colour of flame Conclusion: which element was present?
A
B
C
D
E
F

Conclusion

In order to work out which element was present in each of the solutions, you will need to know the following information:

The colour of the light depends upon the metal:

These colours are also often used in fireworks to give the different colours we see when they burn. Sodium is also used in some street lights and that is why they appear yellow when on. 

If the flame is looked at through a spectroscope it will give a characteristic spectrum. This is used in chemistry to analyse a material for type and concentration of atoms. Chemists ‘burn’ the substance and measure the frequency (colour) of the light given out. This process is called Atomic Emission Spectroscopy.