According to the Bohr Theory of the atom, electrons may occupy only specific energy levels. When an atom absorbs sufficient energy, an electron can “jump” to a higher energy level. Higher energy levels tend to be less stable, however, and if a lower energy level is available, the electron will “fall” back, giving off energy in the process. The difference in energies between the two levels is emitted in the form of a photon of electromagnetic radiation. The energy of each photon is described by the equation E equals h, where h is Planck’s constant and is the frequency of the radiation. If the wavelength of the released photon is between 400 and 700 nm, the energy is emitted as visible light. The color of the light depends on the specific energy change that is taking place.
White light is a continuous spectrum in which all wavelengths of visible light are present. An excited atom, however, produces one or more specific lines in its spectrum, corresponding to the specific changes in energy levels of its electrons. Because each element has a distinct electron configuration, each has a unique line spectrum.
Flame tests are a quick method of producing the characteristic colors of metallic ions. The loosely-held electrons of a metal are easily excited in the flame of a lab burner. The emission of energy in the visible portion of the spectrum as those electrons return to lower energy produces a colored flame. The color is a combination of the wavelengths of each transition, and may be used to determine the identity of the ion.
When you think of The 4th of July or basically any other celebration there is, you always think of fireworks. The thrill of the bursting flames and exciting thunder always makes a party.
The first firework was actually two thousand years ago in China. A cook had accidentally mixed a few household kitchen ingredients, such as KN03, sulfur and charcoal that in turn created gun powder. Over the years this became an art form used in celebrations. They even had professionals who specialized in this art form, called Pyrotechnics’s. In the mid-1600s the art of fireworks spread throughout Europe, where they were used for military purposes. Today they are used for celebrations all over the world.
Fireworks are produced in many stages. First a tube is produced, with one end left open and the other sealed to place chemicals in. A chemical powder is produced, that usually includes potassium nitrate, sulfur and charcoal, and this is called the black powder. The opposite end of the tube is then sealed and a fuse is placed in a hole in one end of the tube.
Each Firework is composed of fuel, an oxidizing agent, reducing agent, regulator, coloring agent and binder. Each of these has their independent role in making a firework function properly.
Charcoal, more commonly know as black powder is usually used as the fuel for fireworks. Fireworks use organic materials for fuel such as charcoal or thermite. The fuel loses electrons to atoms in the oxidizer. It then releases the atoms from the oxidizer. Bonds are then formed between the fuel and the oxygen atoms, creating a product that is relatively stable, but only a small amount of energy is needed. When combustion starts the result is a large release of energy as the solid mixture becomes liquefied and vaporizes into the flame of ignition.
The oxidizing agent is mainly to produce oxygen for the combustion. Then, the reducing agent burns the oxygen provided by the oxidizing agent to create hot gas. Regulators, which are usually metals are used to regulate the speed at which the reaction will occur. The coloring agents are different elements that are added to produce a specific color that the firework will display. For example Lithium produces a purplish red color.
Metal Color
Strontium Red
Copper Blue
Barium Green
Sodium Yellow/Orange
Calcium Orange
Gold Iron
Binders are used to keep the firework together in a paste like mixture. The Binders do not begin to work until the firework is about to be lit.
Today fireworks are used in occasions across the world. They have been used since the middle ages in Western culture to celebrate the birth of kings, queens, princes and princesses. Even today they are still used to celebrate Weddings, anniversaries and more importantly holidays. The Fourth of July is a specific holiday in American culture where fireworks are used every year. Also in our city fireworks are used every year to make the start of the Kentucky Derby Celebration. This firework show, the largest annual show in North America, is called Thunder over Louisville.
Sources:
Reema Gondhia. “The Chemistry of Fireworks” [On line] 29 September, 2007.
Science Museum of Minnesota. “Chemistry in the sky” [On line] 29 September, 2007.
John A. Conkling, Marcel Decker, Inc. “Chemistry of the weeks” [On line] September 29, 2007. http://scifun.chem.wisc.edu/shemweek/fireworks/fireworks.html
Fireworks have been used for recreational and celebratory events for thousands of years. It is ingrained in our culture, especially when considering the Fourth of July and Thunder over Louisville.
If I were to create my own firework show it would include a display with a multitude of colors. The introduction of my show would display bright colors, such as green, orange and red. This would be very exciting for the audience to watch. The middle section would display all colors, a thunderous rainbow in the sky, focusing mainly on the appeal to the eyes. The third and last section of my firework show would then try to appeal to the audience’s heart. It would be a patriotic display of red and blue.
To show the green and orange, my starting sequence, I would need to use two separate chemicals. For orange I would use sodium chloride and for green I would need to use barium nitrate. Both of these elements would help generate a most effective opening display.
During the middle section, which includes my “thunderous rainbow in the sky”, I would use all elements. Chemicals such as: barium, copper, strontium, lithium, potassium, sodium, and calcium. This “rainbow”, so to speak, would “dazzle” the crowd in ways unimaginable.
Finally I would end the show with a very patriotic visual. The sky will burst into color of blue, produced with the element of copper chloride and red, produced by strontium.
This would make my ideal firework show and the elements needed for the show to be made. I am positive that any audience that saw my show would be in awe and astonished with my creativity.
