The physical properties of 1-% mercury-5-% boron-2-% beryllium are as follows:
Mercury, the only metal that is liquid at room temperature, is silver-white and has a metallic luster. Its density is relatively large, 13.59 g/cm3. At standard atmospheric pressure, the melting point is -38.87 ° C, and the boiling point is 356.6 ° C. Mercury has poor thermal conductivity, but good electrical conductivity. Mercury has a certain volatility, and its vapor is highly toxic. Mercury can dissolve many metals to form amalgam. This property has applications in metallurgy and other fields.
Boron, elemental boron has a variety of allotropes. Amorphous boron is a black powder. Crystalline boron is gray-black. Its hardness is second only to diamond, and its texture is more brittle. Boron has a density of 2.34 g/cm3, a melting point of 2076 ° C, and a boiling point of 3927 ° C. Boron is relatively stable at room temperature, and can react with many non-metals at high temperatures. Its electrical conductivity is low, belonging to typical semiconductor materials, and has important uses in the electronics industry.
Beryllium, is steel gray and shiny. The density is small, 1.85 g/cm3, a melting point of 1287 ° C, and a boiling point of 2970 ° C. Beryllium has a higher hardness than metals of the same group, good ductility, and can be made into thin sheets. Beryllium has excellent thermal conductivity, second only to silver, copper, and gold among metals. It also has excellent nuclear properties, such as small absorption cross section for neutrons, large scattering cross section, etc., and has important applications in nuclear reactors. At the same time, most of the compounds of beryllium are highly toxic and should be used with caution.

1 mercury, 5 arsenic, and 2 lead and cadmium are all highly toxic substances, and their uses are related to people's livelihood. However, they also hide serious disasters and cannot be ignored.
Mercury has been used in alchemy techniques. Ancient alchemists, wanting to live forever, used mercury as the base of the pill to refine the so-called elixir. Although this vain move is not advisable, mercury has also had a place in medicine. In the past, elixirs, some of which contained mercury, were used to treat scabies and diseases. However, their toxicity was severe, and if they were not careful, they would harm themselves. And in the metallurgical industry, mercury can be used as a medium for extracting gold and silver, and by the method of amalgam, the precious gold in the mine can be separated.
The use of arsenic also has its uses. In agriculture, arsenic-containing agents were used in the past to repel insects and protect seedlings, and to maintain the prosperity of crops. In the production of pigments, arsenic-containing pigments have bright colors, which can add color to paintings. However, the poison of arsenic is well known to the world. Misuse and accidental ingestion will cause damage to the viscera and worry about life.
Lead and cadmium, both of which are heavy and soft, can be used in construction, as a waterproof material for roof tiles, and in coinage, used to be an important raw material. Cadmium was commonly used in electroplating processes in the past to increase the corrosion and wear resistance of utensils. However, lead and cadmium enter the body, which can easily cause loss of qi and blood, weakness and weakness, especially in children, affect mental development, and cause endless harm.
Although each of these numbers has its own uses, they are extremely toxic. Use them with caution, and they must be controlled by scientific laws and strict regulations. They must not be used lightly because of their use.

To prepare 1-bromo-5-fluoro-2-chlorobenzene, the following ancient methods can be used.
First, halogenation is used. First, a suitable benzene substrate is taken, and in a specific reaction environment, a brominating reagent such as liquid bromine is used. Under the catalysis of a catalyst such as iron filings or iron tribromide, the bromine atom is selected to replace the hydrogen atom on the benzene ring to obtain a bromine-containing intermediate. Then, the reaction conditions are carefully regulated, and fluorine-containing reagents, such as potassium fluoride, are introduced, and the reaction mechanism such as nucleophilic substitution, so that the fluorine atom is also connected to the benzene ring. Finally, a chlorination reagent, such as chlorine, is used in a suitable catalytic system to replace the hydrogen atom at a specific position on the benzene ring with a chlorine atom. After a multi-step halogenation reaction, 1-bromo-5-fluoro-2-chlorobenzene is finally obtained.
Second, the method of functional group conversion. Benzene derivatives containing other convertible functional groups can be prepared first, such as phenyl series containing hydroxyl groups or amino groups. If it is a hydroxyl group, the hydroxyl group can be converted into a halogen atom through a specific reaction, such as hydrogen halide or a halogen-containing reagent under suitable conditions, to achieve the transformation of hydroxyl groups into halogen atoms. If it is an amino group, the amino group can be converted into a halogen atom through diazotization reaction and subsequent reaction with halogenating reagents. After gradual ingenious transformation and regulation of functional groups, bromine, fluorine and chlorine atoms are introduced in an orderly manner to synthesize the target product 1-bromo-5-fluoro-2-chlorobenzene.
Third, in the way of coupling reaction. First prepare different active benzene fragments containing bromine, fluorine and chlorine, such as bromine-containing phenylboronic acid derivatives, fluorine-containing halobenzene and chlorine-containing halobenzene. Then, under the action of transition metal catalysts such as palladium catalysts, through coupling reactions such as Suzuki coupling and Stille coupling, the fragments are connected to each other and skillfully spliced to achieve the synthesis of 1-bromo-5-fluoro-2-chlorobenzene. These coupling reactions have mild conditions and good selectivity, and are quite commonly used in the synthesis of complex halogenated benzene.

1% mercury, 5% arsenic, 2% lead and zinc during storage and transportation, when discussed in the ancient classical Chinese style of "Tiangong Kaiwu", there are many precautions.
Mercury is toxic and volatile. Hidden, it needs to be tightly sealed, preferably a pottery urn, because its material can slow the escape of mercury. Place in a cool and dry place, away from direct sunlight, exposed to sunlight, mercury volatilizes rapidly. When shipping, the package must be firm, wrapped in thick felt, and placed in the vehicle and ship, stable and do not shake to prevent it from dumping. If mercury is released, poisonous gas will overflow and hurt people.
Arsenic, a highly toxic thing. The storage should be placed in a secret room, far away from other things, to prevent it from being contaminated with other things and causing poisoning. The room should be well ventilated, but not close to the fire source. Arsenic is prone to highly toxic gases in case of fire. During transportation, carefully select containers, seal them with metal cans, and wrap them in protective materials, such as thick wooden boxes. Escorts need protective equipment, and the transportation route should avoid crowded places.
Although lead and zinc are slightly less toxic than mercury and arsenic, storage should not be ignored. It should be moisture-proof, moisture is easy to rust, it is appropriate to dry the warehouse, and the ground can be covered with lime to prevent moisture. Stacked in an orderly manner, it is easy to check and use. During transportation, fix it securely to prevent package damage caused by collision. The vehicles or boats used are clean and stain-free, so as not to mix impurities and affect the quality of lead and zinc.
All storage and transportation of these items requires a special person to be responsible, record the entry and exit and flow direction in detail, and follow the rules to ensure safety and avoid disasters.

1% mercury, 5% arsenic, and 2% lead and cadmium are all harmful to the environment and human health.
Mercury is highly toxic. In the natural environment, mercury can be recycled in various ways. Industrial activities such as mining and smelting often cause mercury to be released into the environment. Its gaseous mercury can be transported over a long range and deposited into soil and water bodies through dry and wet deposition. In water bodies, mercury is converted into methylmercury by microbial action, which is particularly toxic. Aquatic organisms are prone to enrich methylmercury. If humans eat fish and shells containing methylmercury, mercury will enter the human body, damage the nervous system, cause cognitive impairment, movement disorders, and pregnant women eat it. Mercury can be transmitted to the fetus through the placenta, causing neurological development and congenital diseases.
Arsenic is also highly toxic. Natural sources such as volcanic eruptions and rock weathering can cause arsenic to enter the environment, and man-made sources such as pesticides and chemicals can also increase arsenic in the environment. High arsenic in soil will inhibit plant growth and reduce crop yield and quality. Excessive arsenic in water bodies can cause skin lesions, such as skin pigmentation and keratinization, and increase the risk of skin cancer, bladder cancer and other cancers over time.
Both lead and cadmium are also extremely harmful. Lead enters the human body, accumulates in bones and teeth, and interferes with the function of the hematopoietic system and nervous system. Children are sensitive to lead, and low-dose lead exposure affects intellectual development, learning and memory. Cadmium is difficult to degrade in the environment and is easily absorbed by plants. People eat cadmium-containing foods for a long time. Cadmium accumulates in the kidney, liver and other organs, damaging kidney function, causing bone pain, osteomalacia, osteoporosis, bone deformity, and pain.
In short, 1% mercury, 5% arsenic, and 2% lead and cadmium are all major threats to the ecological balance of the environment and human health. Efforts should be made to control its emissions and reduce its content in the environment to protect the ecology and human well-being.