Fireworks - OMSI
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©2010 OMSI Fireworks 1. 1. 1. 1. Always wear safety goggles. Caution: DO NOT TOUCH THE FLAME. IT IS VERY HOT. (If the flame goes out, tell a staff person immediately.) 2. 2. 2. 2. Look at the Bunsen burner flame. • What color(s) do you see? 3. 3. 3. 3. Choose one of the solutions. • What color is the liquid? 4. 4. 4. 4. Lift the rubber stopper and lift the wire from the test tube. Make sure there is liquid on the loop. Never touch the wire. It gets very hot. 5. 5. 5. 5. Heat the wire loop in the flame. • Now what color(s) do you see? 6. 6. 6. 6. Dip the wire loop into the rinse beaker to cool it before putting it back into the test tube. 7. 7. 7. 7. Try the other solutions by repeating steps 3,4,5 and 6. • What colors do they make? • Can you identify the mystery chloride? A A A A Closer Closer Closer Closer Look Look Look Look The test tubes contain dissolved metal chloride salts. Each metal solution burns a different color. Using different metals in fireworks creates different colored explosions. The light emitted by different metals can also be used to identify those metals in unknown compounds. In the same way, starlight can be analyzed to find out which metals are present in the star. In the flame, the electrons of the metal receive a boost of energy from the high heat. Excited electrons then return the energy as colored light. Every metal has electrons which absorb different energy and emit different light. This means that each metal gives a characteristic color. What makes the What makes the What makes the What makes the color in fireworks? color in fireworks? color in fireworks? color in fireworks? Can you identify the Can you identify the Can you identify the Can you identify the “mystery chloride” “mystery chloride” “mystery chloride” “mystery chloride” by its flame color? by its flame color? by its flame color? by its flame color?
Transcript of Fireworks - OMSI
©2010 OMSI
Fireworks
1.1.1.1. Always wear safety goggles. Caution: DO NOT TOUCH THE FLAME. IT IS VERY HOT. (If the flame goes out, tell a staff person immediately.)
2.2.2.2. Look at the Bunsen burner flame. • What color(s) do you see?
3.3.3.3. Choose one of the solutions. • What color is the liquid?
4.4.4.4. Lift the rubber stopper and lift the wire from the test tube. Make sure there is liquid on the loop.
Never touch the wire. It gets very hot.
5.5.5.5. Heat the wire loop in the flame. • Now what color(s) do you see?
6.6.6.6. Dip the wire loop into the rinse beaker to cool it before putting it back into the test tube.
7.7.7.7. Try the other solutions by repeating steps 3,4,5 and 6. • What colors do they make? • Can you identify the mystery chloride?
A A A A C lose rC lose rC lose rC lose r LookLookLookLook The test tubes contain dissolved metal chloride salts. Each metal solution burns a different color. Using different metals in fireworks creates different colored explosions. The light emitted by different metals can also be used to identify those metals in unknown compounds. In the same way, starlight can be analyzed to find out which metals are present in the star.
In the flame, the electrons of the metal receive a boost of energy from the high heat. Excited electrons then return the energy as colored light. Every metal has electrons which absorb different energy and emit different light. This means that each metal gives a characteristic color.
What makes the What makes the What makes the What makes the color in fireworks?color in fireworks?color in fireworks?color in fireworks?
Can you identify the Can you identify the Can you identify the Can you identify the “mystery chloride” “mystery chloride” “mystery chloride” “mystery chloride” by its flame color?by its flame color?by its flame color?by its flame color?
Talking Points: Fireworks
Extensions
For best results, encourage them to use the hottest part of the flame (the tip of the cone that points up from the edge of the burner).
Ask the questions: 1) Can you identify the mystery chloride?
Challenge visitors to identify the mystery chloride by matching its color in the flame to the other chlorides.
2) If someone were to sneak in and remove the labels from these test tubes, how could we determine which is which?
By performing the experiments and comparing the colors with samples of the same chloride. This is essentially the method used by chemists to determine the elements in an unknown sample.
Applications
Spectroscopy is the use of light emission to identify the identity and quantity of elements in a compound or mixture. It is a common tool for analytical chemists. The chemist may choose different wave lengths to study, including x-ray, ultraviolet, visible, near-infrared or infrared. Each range is useful for certain investigations. The fact that each element emits characteristic colors when heated is also useful in making fireworks. The various bright colors in the exploding rockets are controlled by including elements that emit light of those colors when burned in an explosion.
In-Depth Information
The energy of the flame moves electrons in the metal atoms to higher energy levels. Some of these electrons will later fall down to lower levels, emitting light. Because the distance between the energy levels for any element is always a constant, the light emitted will have a definite energy, and thus a definite wavelength according to the formula:
E = hγ Where E is the energy of light emitted, γ is the wavelength of the light and h is a constant defined by physicist Max Planck. For a given atom an electron dropping from level 2 to level 1 will emit light at a given wave length. In a spectrometer this will show up as a bar of light at a specific wave length:
Since all of the dissolved salts in this experiment are chlorides (and chlorine atoms do not emit light in the visible range), all of the colors seen are the result of emissions by the metal atoms. Because the spacing of the electron energy levels are different for each metal, the colors emitted are characteristic of each metal and can be used to identify the presence or absence of each metal.
