Color of firework

The colors of fireworks displays are produced by emission from atomic ions as described in Chapter 7. The explosions of fireworks promote electrons to excited states. The energy level scheme of every element is different, so fireworks manufacturers can change colors by incorporating different elements. Sodium ions emit... 

The colors of fireworks depend on the energies of the atomic orbitals of the various atomic ions, but orbital energy levels have consequences that are much more far-reaching. Orbital energies determine the stabilities of atoms and how atoms react. The structure of the periodic table is based on orbital energy levels. In this chapter we explore the details of orbital energies and relate them to the form and structure of the periodic table. This provides the foundation for interpreting chemical behavior patterns. 

From the very ancient art of fireworks come clues about the location and behavior of electrons in atoms. The different colors of fireworks are the result of the actions of elec-... 

In 1823, Herschel [15] in the Transactions of the Royal Society of Edinburgh published his observations of the colors of flames produced by the introduction of alkaline earth salts. The green color obtained with barium salts is due to BaOH and the reddish color characteristic of strontium salts is caused by SrOH. The red colors of fireworks can also be attributed to emission from SrOH [16]. It was not until the 1950s that modern flame studies [17, 18] identified the molecules that are responsible for the alkaline earth flame colors. In contrast to the alkaline earths, the flame colors of the alkali elements are produced by atomic emission. The formation of molecules such as CaOH and SrOH, in fact, greatly complicates the use of flame absorption and emission for the determination of the concentrations of alkaline earth elements in analytical chemistry. 

Each element has a characteristic line spectrum that can be used to identify the element. Note that line emission spectra can also be obtained by heating a salt of a metal with a flame. For instance, common salt (sodium chloride) provides a strong yellow light to the flame coming from excited sodium, while copper salts emit a blue-green light and lithium salts a red light. The colors of fireworks are due to this phenomenon. 

Until now we have dealt with rather simple models of the atom. For example, Dalton s model did not include electrons at all. In order to answer our questions about the colors of fireworks, we need to develop a more complicated model of the atom, and especially of the electrons in the atom. We have not yet looked deeply at the structure of an atom, but that is what this chapter is all about. 

O 78. The "Chemistry in Focus" segment Fireworks discusses some of the chemicals that give rise to the colors of fireworks. How do these colors support the existence of quantized energy levels in atoms ... 

An emission spectrum is produced when atoms in an excited state emit photons characteristic of the eiement as they return to iower energy states. The characteristic colors of fireworks and sodium-vapor streetlights are due to one or a few prominent lines in the emission spectra of the atoms present. 

The answer was to come from an unexpected area the study of colored flames. When metal compounds burn in a flame, they emit bright colors (Figure 7.1). The spectacular colors of fireworks are due to the burning of metal compounds. Lithium and strontium compounds give a deep red color barium compounds, a green color and copper compounds, a bluish-green color. 

Strontium metal is responsible for the red color in fireworks. Fireworks manufacturers use strontium carbonate, which can be produced by combining strontium metal, graphite (C), and oxygen gas. The formation of one mole of SrC03 releases 1220 X 103 k) of energy. 

Eor example, street lamps use the emissions from excited sodium atoms, the dazzling colors of a fireworks display come from photons emitted by metal ions in excited states, and the red light in highway flares often comes from excited Sr ions. 

Copper (Cu) is a bright brown-colored metal. When Cu powder or wire is heated in a high-temperature flame, its characteristic blue-colored emission is observed. Thus, Cu particles are commonly used as a component of aerial shells of fireworks. 

Chemical ingredients of fireworks are chosen to produce specific colors. Barium compounds produce green colors when heated, copper salts produce green and blue flames, sodium salts are yellow in flame, lithium compounds produce red colors, magnesium metal produces brilliant white fight when burned, and strontium compounds produce brilliant red colors. Salts used contain both metallic cations and nonmetallic anions. Anions such as chlorates, perchlorates, and nitrates also contribute oxidizing power to the chemical mixture. 

Uses Picric acid is a white to yellowish, highly flammable crystalline substance. It is used in the manufacture of fireworks, matches, electric batteries, colored glass, explosives, and disinfectants. Pharmaceutical, textile, and leather industries also make use of picric acid. 

Synonyms and trade names picronitric acid, 2,4,6-trinitrophenol, trinitrophenol Use and exposure Picric acid is a white to yellowish crystalline substance and highly flammable. It is used in the manufacture of fireworks, matches, electric batteries, colored glass, explosives, and disinfectants. Pharmaceutical, textile, and leather industries also make use of picric acid. Bouin s picro-formol is used as a preservative solution for biological specimens in laboratories. Toxicity and health effects Picric acid causes different adverse effects on the skins of animals and humans, like allergies, dermatitis, irritation, and sensitization. Absorption of picric acid by the system causes headache, fever, nausea, diarrhea, and coma. In high concentrations, picric acid is known to... 

The blue color in fireworks is often achieved by heating copper(I) chloride (CuCI) to about 1200°C. The hot compound emits blue light having a wavelength of 450 nm. What is the increment of energy (the quantum) that is emitted at 4.50 X 102 nm by CuCI ... 

Yellow colors in fireworks are caused by the 589-nm emission of sodium atoms. Red colors come... 

Tessier introduced the use of cryolite (AlNaaF ) for the yellow coloring of stars, lances, and Bengal lights. In his second edition he includes a chapter on the small pyrotechnic pieces which are knonm as Japanese fireworks, giving formulas for them, and another on the picrates, which he studied extensively. The picrates of sodium, potassium, and ammonium crystallize in the anhydrous condition. Those of barium, strontium, calcium, magnesium, zinc, iron, and copper are hygroscopic and contain considerable water of crystallization which makes them unfit for use in pyrotechnic compositions. Lead picrate, with 1 H3O, detonates... 

Strontium and its compounds have relatively few commercial uses. The pure metal is sometimes combined with other metals to form alloys. An alloy is made by melting and mixing two or more metals. The mixture has different properties than the individual metals. Compounds of strontium are sometimes used to color glass and ceramics. They give a beautiful red color to these materials. Strontium compounds also provide the brilliant red color of certain kinds of fireworks. 

Strontium compounds provide the red color in certain kinds of fireworks. IMAGE COPYRIGHT 2009, VADIM VOLODIN. USED UNDER LICENSE FROM SHUTTERSTOCK.COM. 

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