1 Fluoro 2 Iodo 3 Nitrobenzene

1. ** Uses **:, ancient ointment is also used as "Shen", and its main use is. In terms of work, it is often used for. such as room and utensils, in order to, can protect heavy effect. Because it has a certain stickiness, it can be used to isolate the invasion of external objects, and can make its surface more shiny and add beauty.
2. ** Uses of ointment **: Ointment, there are many uses. First, it is used for. The ancient family mostly used ointment to treat diseases, or apply it externally, or take it. The ointment applied externally can be applied to the mouth, etc., which has the effect of relieving pain and building muscle. Such as gold ointment, it can accelerate the combination of knives and so on. The ointment of clothing often has the power of nourishment and management, like the ointment of nourishment and blood, which can reduce the weakness of the body. Second, it is used for smoothness. In machinery, etc., the ointment can be applied to reduce friction and make the ointment more effective. This is an important use of the ointment in daily utensils.
3. ** Uses of casein **: Casein may not be known to be synthesized in ancient times, but it also has its uses. In terms of food, it is an important ingredient in dairy products. In ancient times, herders, milk and other milk produced casein-related substances, which could be made into cheese and other foods. This food is rich in food, which is easy to preserve and is an important food source in animal husbandry life. Furthermore, in some handmade fields, such as leather, casein can be used for leather tanning. It can make leather softer and more expensive, and improve the quality of leather, so that it can be processed into various leather goods in one step.

Lead is soft and heavy in nature, and its color is blue and gray. At room temperature, the texture is soft, and it can be easily shaped by knife cutting. When heated, it melts, and the melting point is quite low, only more than 300 degrees. This property makes it easy to cast into various utensils. Lead has a high density and feels heavy when placed in the hand. It weighs more than common metals such as iron and copper. And lead has good corrosion resistance. It is not easy to be oxidized in the air. It is placed outside for a long time and only changes slightly on the surface. This property makes it more protective.
Mercury, commonly known as mercury, is the only metal that is liquid at room temperature. It is like mercury, flows flexibly, and has a surface luster like silver. Its fluidity is excellent, it is flexible when shaken, and it fuses quickly. Mercury has a high density. Although it is a liquid, its weight should not be underestimated. Its boiling point is low, about 357 degrees. It is volatile when heated, and the volatile mercury vapor is toxic. If inhaled inadvertently, it will endanger human health.
Germanium has a silver-gray appearance, a metallic luster, and is brittle and hard. Although it is a metal, its conductivity is between a conductor and an insulator, and it is a semiconductor material. This property makes it shine in the field of electronics. The chemical properties of germanium are relatively stable, and it is not easy to react with general chemicals at room temperature. When it encounters strong acids and alkalis, it only acts slowly.
Each of the three has unique physical properties and has important uses in different fields. They are indispensable in casting, chemical protection, and electronic technology. They are indeed precious resources bestowed by nature on mankind.

Mercury is a liquid at room temperature, with a silver-white and metallic luster. It flows easily and is volatile, and its vapor is highly toxic. The culprit of Minamata disease is mercury compounds.
Astatine, one of the halogen elements, is radioactive. Due to its extreme instability and short existence time, relevant research is limited. Its chemical properties may be similar to those of iodine in the same family, but due to radioactivity, many reactions must be very different from those of conventional elements.
Germanium, a metallic element, has semiconductor properties. Its crystal structure is regular, its appearance is silver-gray, and its texture is hard and brittle. In the field of electronics industry, germanium is widely used due to its good semiconductor properties, and can be used to make electronic components such as transistors and integrated circuits. In chemical reactions, germanium can be in the + 2 and + 4 valence states, and can combine with a variety of non-metallic elements. For example, germanium and oxygen can react to form germanium dioxide, which has certain chemical stability.
Of these three, mercury is known for its special physical state and toxicity; astatine is mysterious due to radioactivity and instability; germanium shines brightly in industry due to its semiconductor properties. Its chemical properties vary and play unique roles in different fields. It is a wonderful existence in the chemical world, attracting countless researchers to explore and study.

As described in "Tiangong Kaiwu", there are various ways to make alum. The following are the related production methods of alum:
###gallalum
Gallalum, that is, copper sulfate crystal, its production method is quite exquisite. One method is to find water springs in the place of copper mines. This water contains copper. Dig a pit to gather it, so that the water evaporates naturally. After a long time, the copper in the water gradually crystallizes and adheres to the wall of the pit, which is called gallalum. Ancient craftsmen also often took ores containing copper and calcined them. When the ore encounters fire, the copper is separated from other things, and then it is drizzled with water to obtain a solution containing copper. The solution is placed in an open container, and the water is gradually lost in the sun and wind, and the gallalum is released into the solution. In addition, when iron is reacted with copper sulfate solution, bile alum can also be obtained. Iron is active in copper, put into the copper sulfate solution, iron replaces copper, and the composition of copper sulfate in the solution changes. After subsequent treatment, pure bile alum can be obtained.
##Green alum
Green alum, that is, ferrous sulfate crystals. In mines, find iron-containing ores, mostly pyrite and the like. The ore is crushed and piled up in the open air. After wind and rain, the ore is gradually oxidized. Rain water leaches, and the iron-containing components are dissolved in water and concentrate in low-lying places. Collect this solution, put it in a large kettle, and boil it slowly over low heat. As the water evaporates, the concentration of the solution gradually increases. When the time is right, stop heating, and after cooling, the green alum crystallizes. Another method is to react with iron filings with dilute sulfuric acid. When the iron filings encounter acid, a chemical reaction occurs to form a ferrous sulfate solution. Filtration removes impurities, and then evaporates to concentrate and cool the crystallization steps to obtain green alum.
###Alum
Alum, that is, aluminum potassium sulfate crystals. To prepare alum, alum is often made from minerals containing aluminum, such as alum. The alum is first crushed and then calcined. After calcination, the composition of alum changes. The calcination product is leached in water, so that the aluminum, potassium and other components in it are soluble in water. Filtration removes insoluble impurities to obtain a clear solution. To this solution, add an appropriate amount of sulfuric acid to adjust the proportion of solution components. After that, the solution is evaporated to reduce the water content, and the alum Other aluminium-containing raw materials, such as bauxite, are also used to produce alum through a series of chemical treatments.

Mercury, lead, and tin are the genera that deserve much attention during storage and transportation.
Mercury is naturally mobile and toxic. It can evaporate at room temperature, and its gas is inhaled into the human body, which is very harmful. Therefore, when storing, a sealed device must be used to prevent it from evaporating and escaping. The device should be solid, free of cracks, and placed in a cool, dry place, protected from heat and direct sunlight to prevent it from evaporating rapidly due to heat. During transportation, it should also be carefully wrapped, mostly lined with thick cotton and soft materials to prevent it from being damaged and leaking due to shock. If there is a leak, it should be covered with sulfur powder as soon as possible to make it synthesize into mercury sulfide to reduce its toxicity. < Br >
Lead is heavy and brittle. Storage should be in a dry place, because moisture is easy to cause rust and corrosion. The utensils used can be made of bricks and stones, or special iron boxes should be lined with oil paper and other objects to prevent moisture and corrosion. During transportation, fix it firmly to prevent damage due to shaking and collision during transportation. Handlers should use protective equipment, such as gloves, masks, etc., to prevent lead dust from entering the body.
Tin is milder in nature, but there are also concerns. When storing, it should be avoided from high temperature, which is easy to melt and deform tin. Its soft quality, so the stacking should not be too high to prevent extrusion deformation. During transportation, handle with care and space with soft objects to prevent collisions and damage to their shape.
All these objects, when stored and transported, should be handled with caution according to their physical properties, and should not be slack a little, in order to keep them intact and avoid accidents.