1 Bromo 4 Chloro 2 Iodobenzene

"Tiangong Kaiwu" was written by Song Yingxing in the Ming Dynasty, and it is also a book of all kinds of technological creations. Today, the physical properties of mercury, alum, and saltpeter should be solved as described in the book.
Mercury, commonly known as mercury, is a liquid metal. Its color is silver-white, with a metallic luster, and its weight. At room temperature, mercury is in a flowing state and is highly volatile, and the evaporated mercury vapor is highly toxic. The melting point of mercury is extremely low, about -38.87 ° C, and the boiling point is not very high, about 356.6 ° C. Its chemical properties are relatively stable, and it can react when it encounters strong oxidizing agents. In ancient times, mercury was often used by alchemists and was also used in gold gilting and other processes.
Alum, there are many kinds, common alum, green alum, etc. Alum, chemical name aluminum sulfate potassium dodecahydrate, is a colorless transparent block crystal or crystalline powder, sweet and sour taste. It is easily soluble in water, the aqueous solution is acidic, hydrolyzed in water to form aluminum hydroxide colloidal precipitation, this characteristic makes it often used as a water purifier. Green alum, that is, ferrous sulfate heptahydrate, is light blue-green monoclinic crystal, easily oxidized when exposed to air, and the surface gradually changes to yellow-brown. Green alum can be used as fertilizer in agriculture to supplement the iron element of the soil, and is also used in pharmaceuticals and other fields.
Saltpeter, the main component is potassium nitrate. It is a colorless transparent orthorhombic crystal or rhombus crystal or white powder, odorless, non-toxic, salty and cool. It is slightly deliquescent in the air, easily soluble in water, and the solubility increases significantly with the increase of temperature. Saltpeter decomposes when heated and releases oxygen. This property makes it an important component of gunpowder in ancient times, and it is also used in the production of glass and other processes.
Mercury, alum, and saltpeter each have their own unique physical properties and are important in different processes and fields. This is a corner of the general physical properties recorded in Tiangong Kaiwu, which shows the wonder of the ancient people's understanding and application of objects.

Mercury, bromine, and iodine are all important substances in chemistry, each with unique chemical properties.
Mercury, commonly known as mercury, is the only metal that exists as a liquid at room temperature and pressure. Its chemical properties are relatively stable, and it is not easy to react with common gases such as oxygen at room temperature. However, mercury can react quickly with sulphur powder to form mercury sulfide, which is often used to treat spilled mercury. Mercury can also react with strong oxidizing acids such as nitric acid to form corresponding mercury salts. Mercury compounds are many toxic. When using mercury and its compounds in industry and life, it is necessary to take care to prevent its harm to the environment and human body.
Bromine is a lively non-metallic element. It is a dark reddish-brown liquid at room temperature and is volatile. Bromine is chemically active and highly oxidizing. Bromine can react with metal elements, such as reacting with iron to form iron bromide. Bromine can also react with many organic compounds in substitution and addition reactions, and is widely used in the field of organic synthesis. For example, bromine and ethylene can undergo an addition reaction to fade bromine water, which is an important method for testing olefins.
Iodine is a purple-black solid at room temperature, which is easy to sublimate. Iodine is slightly less oxidizing than bromine, but it can still react with some metals, such as sodium to form sodium iodide. Iodine elements will show a special blue color when exposed to starch, and this property is often used to test the presence of iodine elements or starch. In the human body, iodine is a key raw material for the synthesis of thyroid hormones and is essential for maintaining normal physiological functions of the human body.
The differences in the chemical properties of mercury, bromine, and iodine have indispensable uses and important significance in many fields such as chemical industry, medicine, and scientific research.

The common synthesis methods of mercury, bromine, xenon, and thallium each have their own techniques, as detailed below:
Mercury is often refined from cinnabar (mercury sulfide). In ancient times, cinnabar was placed in a furnace and burned with charcoal fire, sulfur and oxygenation escaped, and mercury precipitated. The "Tiangong Kaiwu" also states, "Where cinnabar and mercury are, that is, the liquid of Dan sand. The ancient scriptures say that Dan sand was exposed to the qi of Qingyang, and began to produce ore. In two hundred years, it became Dan sand and a young woman was pregnant. In three hundred years, it became lead, and in two hundred years, it became silver, and in two hundred years, it regained the qi of Taihe, and turned into gold. However, the power of Dan sand can produce gold, and gold can be received from Dan sand, don't you believe it?" First crush the cinnabar, put it into a special stove, seal it, and heat it to the right temperature. Due to the low boiling point of mercury, it is easy to gasify when heated. After condensation, gaseous mercury is reduced to a liquid state and can be collected.
The synthesis of bromine is mostly taken from seawater or brine. Seawater contains bromide. First, chlorine is added to these solutions. The oxidation of chlorine is stronger than that of bromine, so bromine ions can be replaced. The reaction is as follows: 2Br + Cl ² = Br ² + 2Cl. After that, because bromine is volatile, air blowing is used to make bromine-containing air pass through the absorption tower and absorb it with an aqueous solution of sulfur dioxide to generate hydrobromic acid. Then hydrobromic acid is oxidized with chlorine to recover bromine. Although this process is slightly complicated, it is a common preparation method.
Xenon is a rare gas with a very small content in the air. In industry, it is often obtained from fractionation of liquid air. Because the boiling point of xenon is different from other gases, the temperature can be controlled and separated one by one. When the liquid air heats up, nitrogen, oxygen, etc. are first vaporized and escaped, while xenon remains in the remaining liquid, and then further distilled and purified to obtain high-purity xenon gas.
The preparation of thallium is often obtained from the by-products of sulfide ores such as lead, zinc, and copper. During ore smelting, thallium is enriched in soot or waste residue. First, these materials are leached with acid to dissolve thallium and form ionic states. Then by chemical precipitation or ion exchange method, thallium ions are separated and enriched, and finally by reduction reaction, such as replacement with active metals (zinc, etc.), or electrolysis, thallium ions are obtained electrons and metal thallium is precipitated.

Arsenic, mercury, cinnabar and other substances are used in many places, according to the records in "Tiangong Kaiwu".
Arsenic was occasionally involved in ancient alchemy. Although it was absurd, it was also one of the explorations at that time. In the field of medicine, in the medical records of specific diseases, a very small amount of arsenic was processed or used in the method of fighting poison with poison, but this method needs to be cautious, and a slight mistake will endanger life. In agricultural deworming, there are also attempts to use a little arsenic to use its toxicity to drive out pests. However, it is quite harmful to the environment and humans and animals, and it is not a long-term solution.
Mercury is very useful in the construction of ancient imperial tombs. In Qin Shi Huang's mausoleum, mercury is used as a hundred rivers and seas, simulating the water veins of the world. One symbolizes that the emperor controls the rivers and rivers in the world, and the other is that mercury evaporates highly toxic to prevent tomb robbers. In alchemy, mercury is an important raw material, and alchemists thought it could refine miraculous medicinal pills, but in fact it often caused poisoning. In medicine, the ancients believed that mercury could be used as medicine to treat scabies and sores, etc. However, its toxicity is strong and the risk of use is high.
Cinnabar, its bright red color, is often used as a painting pigment to add color to murals, calligraphy and painting and other works. In religious rituals, cinnabar has mysterious significance and is often used to draw spells. The ancients believed that it can exorcise evil spirits and suppress evil spirits. In alchemy, cinnabar was also commonly used. Alchemists believed that it contained the spiritual energy of heaven and earth, and after refining, they could obtain the elixir of longevity. However, its main ingredient, mercury sulfide, was heated to decompose mercury, which was significantly toxic.
Although arsenic, mercury, and cinnabar were used in some fields in ancient times, they were all highly toxic, so they needed to be used with extreme caution. With the development of the times and the progress of cognition, modern times have mostly abandoned their dangerous uses.

All kinds of utensils have their own prices among the shops of Guanfu City. However, if you want to know the value of "1 + - + alkali + - + 4 + - + alum + - + 2 + - + stone", you need to study it carefully.
The pricing of the market is not determined in one way. First, it depends on the material. If the material is rare, its price must be high; if the quarry, alum, or stone is obtained from a remote place, it is difficult to collect, or it is originally a rare mine, it is naturally valuable. Second, it is related to the work of production. If the production is fine, labor-intensive, and the craftsmanship is complicated, the price will be high; if the craftsman carves the stone, finely crafted, and the texture is exquisite, the price will also rise. Third, the current supply and demand are also the main reasons. If people compete for this "1 + - +++ - + 4 + - + alum + - + 2 + - + stone", the demand is strong, and the supply is limited, the price will rise; on the contrary, if no one cares, the supply will exceed the demand, and the price will decrease.
However, I have not seen the actual product of this "1 + - + alkali + - + 4 + - + alum + - + 2 + - + stone" in person, nor have I known its uses and advantages and disadvantages in the current world. It is difficult to determine the price of its market. But according to common sense, if the material is ordinary, the production is not very special, and it is not urgently needed, its price may be moderate; if the material is rare, the craftsmanship is excellent, and it is sought by everyone, the price must be high. It is necessary to be in the market, consult merchants and craftsmen, and carefully observe its quality and use, in order to obtain its more accurate market value.