Name_____________________________________ Period_____ Date_____
Flame Tests for Metals Lab
To observe and identify metallic ions using flame tests.
Introduction ; The characteristic yellow of a candle flame comes from the glow of
burning carbon fragments. The carbon fragments are produced by the incomplete
combustion reaction of the wick and candle wax. When elements, such as carbon,
are heated to high temperatures, some of their electrons are excited to higher
energy levels. When these excited electrons fall back to lower energy levels, they
release excess energy in packages of light called photons, or light quanta.
The color of the emitted light depends on its energy. Blue light is more
energetic than red light, for example. When heated, each element emits a
characteristic pattern of light energies, which is useful for identifying the
element. The characteristic colors of light produced when substances are heated
in the flame of a gas burner are the basis of flame tests for several elements.
In this experiment, you will perform the flame tests used to identify several
5 cotton swabs 5 solutions pencil or pen
Goggles lab apron Bunsen burner
BEFORE DOING THE LAB, ANSWER THE PRE-LAB QUESTIONS
1. Obtain the solutions containing the metal ions from your instructor.
2. Put on the safety gear and light the Bunsen burner.
3. Dip a cotton swab into the solution you are going to test and then place it in
the edge of the flame. Note the color of the flame in the data table below.
NOTE: Don’t leave the cotton swab in the flame long enough to burn it.
4. Do the same thing for the other solutions.
Answer the following questions to make sure you understand the background
1. What did Earnest Rutherford’s gold foil experiment demonstrate about the
composition of an atom?
2. What happens to an atom’s electrons when exposed to excess energy?
3. What is released when an atom’s electrons lose energy and return to its
Solution Color when heated
Analyses and Conclusions:
1. Why did different chemicals emit different colors of light?
2. Why do you think the chemicals had to be heated in the flame for the
colored light to be emitted?
3. Using what you know about wavelengths, frequency, and energy, list the
metallic elements used in the flame test in increasing order of the energy
of the light emitted.
4. How does the flame test provide support for quantized energy levels?
Explain your answer.