Whenever the festival or grand event comes, fireworks are often set off to increase the atmosphere
When colorful fireworks bloom in the dark night, accompanied by a loud "boo" sound, fireworks soar into the sky, and in an instant, red, yellow, purple, blue fireworks of various colors crisscross each other, like meteors falling.
When we feel joy and happiness, have we ever thought about how these colorful colors are formed?
The structure of fireworks
Fireworks, also known as fireworks, fireworks. After the invention of gunpowder, there were fireworks, so it can also be called one of the four major inventions of ancient China.
The structure of fireworks and firecrackers is very similar, both use black powder as a medicine guide, gunpowder agent will send fireworks into the sky when the space explodes, when the gunpowder burns in the high altitude, explodes, it forms fireworks.
Image source: hippopx
The effect of fireworks
The reason why fireworks can bloom colorful is mainly because of the "flame color" reaction. During the fireworks production process, the production staff will add some metal luminescent agents and coloring agents quantitatively.
Metal luminescent agents are mainly aluminum powder and magnesium powder, which emit a dazzling white light when fully burned in oxygen. The coloring agent is mainly some metal compounds, and the metal and oxygen ions in the metal compound combine to react violently, which will produce different colors of light.
What is the flame reaction? Flame color reaction is also known as flame color test and flame color test. It is the reaction of certain metals, or their volatile compounds, that cause the flame to take on a special color when it burns in a colorless flame. The principle of the flame color reaction is the "identity card" contained in each chemical element - the characteristic spectrum.
Because some of the spectral lines of elements such as sodium and strontium dominate the spectrum, its flame color reaction is extremely obvious, and colored fireworks usually use these metal elements.
At this point, many people will think that this is a chemical reaction, but the fact is: the flame color reaction is a physical change.
Because it does not produce new materials, it is mainly a change in the electronic energy level inside the substance, and does not involve changes in chemical properties and its own material structure.
Different types of metal compounds produce different colors when burned in the air, so we often use the color produced after combustion to identify which metal compound is.
Examples are several common colors: the flame reaction produced by sodium when burning is yellow, the copper element is green, and potassium is usually light purple, but because potassium is usually doped with some sodium, we often use blue cobalt glass to observe.
The people who make fireworks will skillfully sort these substances to determine the order of combustion, and we see colorful and colorful fireworks, which are actually "electronic" dancing.
After clarifying the color of the fireworks, let's continue to dive into the sound effects of fireworks.
When the gunpowder agent explodes in space, it produces a large amount of gas, and some gases can make beautiful flutes and whistles through the gaps in the nozzles. Some gases have a stronger explosive ability, and can directly blow up the container to produce a bursting sound and a buzzing sound of "aftershocks".
In layman's terms, the sound effect of fireworks produces a principle similar to that of wind music, and different instruments can produce different timbres under the air flow.
Atmospheric Invisible Killer: Fireworks
Although fireworks are beautiful, they release a large amount of air pollutants during the process of firing. The main components of "acid rain": sulfur dioxide, nitric oxide, nitrogen dioxide, etc., are the gases produced when fireworks are fired. These gases not only cause harm to the atmosphere, but also affect the body's respiratory system and cardiovascular system.
In 1990, on the eve of the Spring Festival in Dandong City, Liaoning Province, fireworks and firecrackers sounded in unison, and according to the test of environmental protection station personnel, the harm of these gases was equivalent to a major pollution accident. With the development of the times and the progress of science and technology, more and more people began to care about environmental protection issues, so electronic fireworks were born.
Electronic fireworks do not use black powder and medicinal introduction, the use of internal electronic components, through the light reflector, color chips to produce the traditional fireworks after the explosion of the brilliant colorful. For example, Hebei held an electronic fireworks exhibition, and after the exhibition, not only did not produce too much pungent smell after the burning of gunpowder, but also did not have the garbage generated after the traditional fireworks were fired. Electronic fireworks can also be recycled, which is both environmentally friendly and beautiful.
However, compared with traditional fireworks, because electronic fireworks are newly developed, there is no large number of popularity in the market, and the public cannot buy them.
In the past, fireworks were set off to ward off evil spirits, but now, fireworks mean more noise and atmospheric pollution. Although fireworks are brilliant and colorful, we should try to avoid too much burden on the environment.
END
Audit specialists
Yafei Sun, Ph.D. in Chemistry, Tsinghua University.
Tadpole stave original article, reprinted indicating the source
Editor-in-charge/Heart & Paper
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