Chemistry

Fluorine is called the "death element" and stems from the extremely difficult process of separating and preparing simple fluorine. Its chemical properties are active and highly toxic. Many researchers such as David and the Knox brothers have been poisoned and even sacrificed for this. After years of exploration, French chemist Mouisant successfully electrolyzed the preparation of simple fluorine for the first time in 1886 and won the Nobel Prize in Chemistry. He died early due to exposure to poison.

Although rare gases are rare and chemically inactive, they show special abilities in many fields. Liquid helium is used in ultra-low temperature technology, neon gas is used for fog transparent lights, argon gas is used for cosmic radiation detection, krypton gas is used for X-ray shading, xenon gas is used for photodegradation and medical treatment, and mixed gas lasers help high-tech measurement and communication promote development in multiple fields.

This paper focuses on the evolution of the names of rare gases, explaining that rare gases are six gases with low content in the atmosphere. In the early days, they were called "inert gases" due to their stable atomic structure and extremely inactive chemical properties; in 1962, Bartlett synthesized xenon compounds, overthrowing the conclusion that it is completely inert, so it is now renamed rare gases.

This paper combs the evolution of the definition of elements, from the ancient Eastern and Western views to Lavoisier's redefinition of elements in modern times. It details Mendeleev overcoming difficulties to discover the periodic law of elements and predict unknown elements. Later, Mosley revealed the essence of the periodic law and cracked the code of elements.

This article answers the question of whether LCD displays are made of crystals. Introduce the liquid crystal discovered in the 19th century: a substance between solid and liquid, which has both fluidity and crystal optical and electrical properties; explain its molecular structure, and use voltage to change the arrangement to achieve display. LCD has become the mainstream because of its thinness and low power consumption, making it clear what It is used as a liquid crystal rather than an ordinary crystal.

This paper explains that salt particles are cubic, originating from the regular stacking of sodium chloride ions and chloride ions in the interior; introduces the widespread existence of crystals, enumerates common crystals, which have been observed by the ancients for a long time, and points out that the essence of crystals is the regular arrangement of internal particles rather than the shape, for example, glass is non-crystal, metal is crystal, etc.

In response to the question of 'Will the oxygen on the earth be used up?' This paper uses the green leaf experiment of Swiss scientist Scheniber to confirm that plants can release oxygen through chlorophyll and use carbon dioxide for photosynthesis in the sun. The oxygen consumed can be continuously replenished by green plants., so the oxygen will not be exhausted.

This article explains the two core reasons why the air is exceptionally fresh after a thunderstorm: one is that heavy rain washes away most of the dust in the air, and the other is that lightning produces a small amount of thin ozone to bring freshness; it also introduces the structure, production principle, oxidation and water purification effect of ozone. Mentioning that pine forests also release ozone.

This article explains that the air is not "empty". It tells the story of Swedish pharmacist Carl Scheler's experiment in burning yellow phosphorus in a closed air bottle and found that the water rose by about 1/5, and the remaining gas did not support combustion; Lavoisier's research clarified the composition of air, such as oxygen is about 21%, nitrogen is about 78%, etc., which proves that air is actually a mixture of multiple gases.

This article focuses on "whether it is good to drink distilled water alone" and introduces the preparation principle of distilled water and its relatively clean characteristics. It points out that drinking distilled water for a long time is not conducive to health due to the lack of minerals. It is recommended to drink boiled water (sterilize and retain minerals). You can also drink distilled water with added minerals and match it with mineral-containing dishes.

This article focuses on 'Why can water extinguish fires' and points out that water is the nemesis of fire. The core reason for extinguishing fires is that water is the product of the combustion of hydrogen in oxygen. It is non-flammable. When heated and vaporized, it can absorb heat, cool down and isolate oxygen; at the same time, it explains that oil fires cannot be used with water. Because oil is lighter than water, it will spread, so it needs to be disposed of with a fire extinguisher or sand.

This article is a popular science work that focuses on the question of "what is water" and points out that the answer to "water is water" in the past was unscientific. It tells the story of the 18th century chemist Joseph Priestley's experiment by mixing and burning hydrogen and air to produce water droplets., confirming that water is composed of hydrogen and oxygen, and subsequently clarifying the molecular structure of water and the method of electrolyzing water to verify the composition.