Chemistry

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.

Carbon has four electrons in its outermost shell, making it difficult to achieve a stable structure by gaining or losing electrons. Therefore, it often combines by sharing electrons. Furthermore, carbon atoms can form long chains or ring structures by...

When the outermost electron shell of an atom is not fully filled, they will combine with each other by transferring or sharing electrons. This process "tethers" atoms together to form molecules, which is the basis for the existence of all things and...

In the past, people believed that atoms could not be split, and the phenomenon of radium releasing huge amounts of energy over a long period of time raised questions. Later, Rutherford and others discovered that atoms could be split, and atomic energy ...

In the early 20th century, people discovered that atoms are composed of electrons and a nucleus. The nucleus can be further divided into various "elementary particles," of which about 400 have been discovered so far. These elementary particles have...