When a chemical element is named, it often has a certain meaning, either to commemorate the place of discovery, or to commemorate a scientist, or to express some characteristics of this element. For example, the original meaning of europium is "Europe". Because it was found in Europe. Americium originally meant "America" because it was discovered in America. For another example, the original meaning of germanium is Germany, the original meaning of scandium is Scandinavia, the original meaning of lutetium is Paris, and the original meaning of gallium is home to Asia, which is an ancient name of France. As for polonium, the original meaning is Poland. Although it was not found in Poland, it was found in France, but the discoverer Madame Curie was Polish. She named it polonium in memory of her motherland. There are many names of chemical elements to commemorate a scientist, such as "Ru" to commemorate Mendeleev, the discoverer of the periodic law of chemical elements, "Ru" to commemorate the Curie couple, and "Ru" to commemorate the Swedish scientist Nobel.
There are more and more examples of naming to express a certain characteristic of an element. Such as cesium (sky blue), rubidium (crimson), thallium (Latin for green bud), indium (indigo), argon (inert), radon (emanation) and so on. In addition, such as nitrogen (inanimate), iodine (purple), radium (radiation) and so on. , is also named according to some characteristics of the element.
Qin Shihuang dreamed that the throne would last forever, and the dragon body would last forever. He thought about medicine every day and dreamed of gold and silver at night. So all the immortals made great efforts to refine the elixir. They lived in seclusion in Shan Ye, and lived an immortal life. The alchemist used cinnabar (mercury sulfide) and realgar (arsenic sulfide) as raw materials, and started smelting. Trying alchemy, turning stone into gold, taking elixir or using gold and silver as dishes will make people immortal. Foreigners in western languages also imitate darkrooms or caves, are single and widowed, and devote themselves to alchemy. One or two thousand years passed, and many people died in the elixir. And then disappeared in vain. Ancient Chinese and foreign alchemists engaged in chemical experiments all their lives, why did they accomplish nothing? Because it violates the laws of science. They dream of using simple legislation such as sublimation to change the nature of base metals and turn lead, copper, iron and mercury into valuable gold and silver. I don't know that the nature of elements can't be changed by general chemical legislation. Chemical elements are the general name of the same kind of atoms with the same nuclear charge number, and atoms are the smallest particles in classical changes. In chemical reactions, molecules can be divided into atoms, but atoms cannot be divided. With the development of science, today "turning stone into gold" has been realized. 19 19, Rutherford, England bombarded nitrogen with alpha particles to change nitrogen into oxygen. 194 1 year, scientists use atomic accelerators to change mercury into gold-artificial gold americium (element 100). 1980, American scientists bombarded bismuth metal targets with neon and carbon atoms at high speed, and obtained a small amount of gold with a large needle tip. Then warlocks will be ashamed to know the great achievements of today's people.
Wonderful use of copper sulfate
In hot summer, when you jump into the light blue swimming pool to swim, do you know that the water in this pool is a very dilute copper sulfate solution, which is used to kill the bacteria brought by many swimmers to ensure the health of all swimmers?
In medicine, copper sulfate is also used as emetic. Doctors often use copper sulfate to induce vomiting when you eat unclean things or take toxic things by mistake.
Perhaps you are most interested in copper sulfate or an effective anti-shark drug!
If we want to talk about shark medicine, we have to start from World War II. In order to occupy the whole world, fascism spread the war to Europe and Asia, and the naval battles in the Atlantic and Pacific were unprecedented cruel. In the naval battle, a large number of ships were sunk by the other side, and the surviving officers and men on board abandoned the ship and fled for their lives. But these fugitives are still born to die, because there are many hungry sharks waiting for them in the ocean. In order to prevent its officers and men from being besieged and swallowed by sharks, the US government called on people of insight all over the country to study anti-shark drugs. Many scientists and people from all walks of life responded and put into experiments to stop sharks with drugs.
At that time, there was a famous literary master named Hemingway, who also circled a sea surface in his familiar sea area and began the experiment of preventing sharks with drugs. He alternately placed baits with and without copper sulfate on the sea surface to observe what sharks would do.
Two days later, when he went to check these baits by boat, he was surprised to find that the shark had eaten all the baits without copper sulfate, but the baits with copper sulfate had not changed. Hemingway jumped for joy. He finally used a simple and common salt-copper sulfate to prevent sharks.
Soon, the officers and men of the US Navy were equipped with this "amulet" made of copper sulfate to prevent sharks.
Fire-breathing old cow
Such a strange thing happened in a small mountain village in Holland. A vet treated an old cow. Niu Yi people looked up and down, his hooves kept banging on the ground, like ants on hot bricks. In recent days, it can't eat feed. The belly is round. Fingers ring when they knock. Veterinary diagnosis showed that the cow had flatulence. In order to check whether the gas in the cow's stomach is discharged through the mouth. Then he put a probe into the cow's throat. When he lit a lighter in front of the cow's mouth to prepare for observation, he never expected that the gas produced in the cow's stomach would burn violently and spray a long flame from the cow's mouth.
The vet was surprised when he saw it and quickly stepped back; Niu Yi was frightened when he saw the fire. I broke the reins and jumped around in the cowshed, burning grass and causing a raging fire. Although veterinarians and others tried their best to rescue them, it didn't help. The whole cowshed and pasture were reduced to ashes.
Why does this cow breathe fire?
Through the research and analysis of relevant personnel, it is concluded that the gas emitted by cattle is methane.
The molecular formula of methane is CH4, and bubbles often escape from the bottom of the swamp, which is it, hence the name biogas. It is a colorless and odorless gas with relatively stable chemical properties. It can burn and generate a lot of heat. Therefore, it is a kind of fuel. Organic wastes, such as human and animal manure, wheat straw, stems and leaves, weeds, leaves and other substances containing cellulose, are used as raw materials for biogas fermentation. Methane is produced due to the action of microorganisms.
Knowing the conditions of methane production, we can easily find out why cows breathe fire. Cattle eat forage grass, the main component of which is cellulose. Because cows are sick and have weak digestive function, abnormal fermentation in the stomach produces a lot of methane, which causes flatulence. When the veterinarian inserts the probe, it will pump out gas like a catheter. Methane is flammable, so it will burn in case of fire, which will cause a fire.
From Napoleon to Blonde
There is a story: 18 14, Napoleon was captured and exiled and died in St. Helena. According to encyclopedia americana, he died of stomach trouble. For many years, the French thought that he was poisoned by the British. But no one can produce reliable evidence. The death of the monarch has become a mystery left over by history! 150 years later, scientists discovered a hair of Napoleon. If it is a treasure, they cut it into small pieces and put it in an atomic reactor for neutron reflection. It was found that the arsenic content in hair was 40 times that of normal people. Therefore, it is confirmed that the man who was all-powerful in Europe in the19th century died of arsenic poisoning.
Why can fine hair solve the mystery of Napoleon's death? It turns out that hair, like blood, also contains dozens of trace elements, which can accurately show a person's health. Although it is inconclusive whether Napoleon died of man-made poisoning or endemic arsenic poisoning, it is true that the arsenic content in food and domestic water on St. Helena is high.
Today's chemistry confirms that the color of hair and its changes are related to the concentration of metal elements. Black hair contains molybdenum; Red-brown hair contains copper, iron and cobalt; When the nickel content in hair increases, it will turn gray. Conversely, from the change of hair color, we can reveal the real picture of environmental pollution. There are two blondes in San Francisco, USA. The beautiful blonde gradually turns green. In the final analysis, it is because of the copper pollution in the copper mine where they live.
Hair is like an environmental monitor, always reminding people whether your living environment is polluted and what elements are at work, so as to take corresponding countermeasures.
A large number of chemical analysis shows that the lead content in the hair of urban residents is much higher than that of rural residents, which is caused by the long-term inhalation of lead-containing exhaust gas from automobiles by urban residents. Residents near traffic chaos lines and workers engaged in lead operations have higher lead content in their hair; People who live by the sea and eat fish and shrimp three times a day have several times higher mercury content in their hair than mainlanders.
With the progress of science and technology, it will add luster to people's bodybuilding and will become a reliable environmental pollution monitoring post.
Clever reaction of acetic acid to hidden information in eggs
Acetic acid, also known as acetic acid, is a colorless liquid with a strong pungent smell and a low melting point. When the room temperature is lower than 16.6℃, acetic acid can easily condense into ice-like solid. Anhydrous acetic acid is also called glacial acetic acid. Acetic acid is easily soluble in water and ethanol, and has the generality of acid, which can produce esterification reaction. Acetic acid is the earliest acid used by human beings and can be used for seasoning. Acetic acid is widely used in industry, which is an important chemical raw material, and can also be used to produce medicine, pesticides and so on. In addition, acetic acid also contributed to the transmission of information in wartime.
During the First World War, there were many French sentries at the junction of Germany and France on the front line of the Sougou River, and they made a strict investigation of passers-by. One day, a German peasant woman was questioned while carrying a basket across the border. The basket is full of eggs, and there is nothing suspicious. A young active sentry grabbed an egg, threw it into the air unconsciously, and then caught it. At this time, the peasant woman immediately became very nervous, which led to the sentry's pregnancy. When the egg was opened, I saw that the egg white was covered with handwriting and symbols.
It turns out that this is a detailed map of British protection, with the division and brigade numbers on it. This method was provided to the intelligence personnel by a chemist in Germany. The method is simple: write it on the eggshell with acetic acid, and when the acetic acid dries, there will be no trace. But if the egg is cooked again, the handwriting will miraculously be printed on the egg white through the eggshell.
Why can chemists come up with clever ideas to hide secrets in their eggs? This is mainly the result of the reaction between acetic acid and other substances. The main component of eggshell is calcium carbonate. When writing with acetic acid, acetic acid reacts with calcium carbonate in eggshell to produce calcium acetate, and then acetic acid reacts with egg white through eggshell. Egg white is a soluble protein, and protein is a chain polymer compound composed of amide bonds formed by dehydration of several α -amino acids. Unstable under heat, ultraviolet rays or chemical reagents such as nitric acid, trichloroacetic acid, tannic acid, picric acid, heavy metal salts and urea. The infiltrated acetic acid reacts with the egg white, leaving a special mark on the egg white. After the eggs are cooked, there will be clear and legible handwriting. So chemists skillfully use acetic acid to react, and the information is hidden in eggs.
Mystery of "Ghost Valley"
In the northwest of North America, there is a very wide valley. Many Indians lived here as early as15th century ago. Strangely, local people often suddenly get sick, lose their hair, lose their eyes, and then die painfully. Even some animals can't escape the fate of death, so it didn't take long for this place to be deserted. Because this valley is so terrible, people call this place "Ghost Valley". Why do people get this strange disease?
After World War II, some brave geologists broke into the "Ghost Valley" again. After their field investigation and experiments, it was found that the soil here contains a lot of selenium. Selenium enters the human body through the "transmission" of plants and rivers. Excessive selenium content in human body will lead to poisoning and death.
Modern scientific research shows that selenium is one of the essential trace elements for human body. If selenium is deficient, it will also cause diseases. In the past, Keshan disease often spread in Keshan County, Heilongjiang Province, China, which was caused by selenium deficiency. He was very ill, and the patient began to vomit yellow water, then heart failure and finally sudden death. Later, the researchers sprayed a compound called sodium selenite on crops. After people eat these plants, the selenium content is properly supplemented, thus controlling the occurrence of Keshan disease.
Now, the mystery of the "Ghost Valley" has been unveiled, and scientists have adapted to local conditions and turned it into a selenium mine. People planted a plant called Chinese milk vetch in this valley. Because Chinese milk vetch has the ability to eat selenium. After a long time, Chinese milk vetch will accumulate a lot of selenium. When Chinese milk vetch is mature, it can be cut into sections, dried in the sun, burned to ashes, and a small amount of selenium can be extracted. It is said that 2.5 kg of pure selenium can be extracted from 1 ha of Chinese milk vetch after it is burned to ashes.
1, iodine and fingerprints solve the case
Students often see the plot of public security personnel using fingerprints to solve crimes in movies. In fact, as long as we put our hands on a piece of white paper, then point our fingers on the paper at the mouth of the test tube containing a small amount of iodine and heat the bottom of the test tube with an alcohol lamp. When the sublimated purple iodine vapor in the test tube comes into contact with the paper, the fingerprints that are usually invisible on the paper will gradually appear, and very obvious brown fingerprints can be obtained. If you put this piece of white paper away and do the above experiment a few months later, you can still show the fingerprints hidden on the paper.
This is because everyone's fingerprints are not exactly the same. Fingers always contain grease, mineral oil and sweat. When you press your finger up on the paper, the grease, mineral oil and sweat on the fingerprint will remain on the paper, but it is invisible to the human eye. Pure iodine is a purple-black crystal with metallic luster. Interestingly, when most substances are heated, they generally change in three States: solid, liquid and gas. Iodine, on the other hand, is uncharacteristic. After heating, it can be directly turned into steam without liquid. The phenomenon of direct gasification of solid matter like this is called sublimation. At the same time, iodine is also soluble in organic solvents. When iodine vapor rises, it will dissolve in these organic solvents, so fingerprints will appear.
2. Who is the murderer?
The mountain village bathed in the morning light woke up from sleep. Looking up, flocks of cattle and sheep were running and playing on the green hillside. Chickens cackling for food, ducks quacking for food ... Suddenly, bursts of laughter came and followed. It turned out that the girl was dressed by the lake, the green lake was everywhere, and the children in the village were still playing around ... However, today, the vitality of the mountain village has disappeared, and even the morning light seems to have lost its luster. In front of people is a dazzling array of dead bodies and killed cattle and sheep. Creatures no longer exist here, which is really terrible and shocking. This is a set of realistic footage of the Loch Ness tragedy broadcast by CCTV. It never rains but it pours. In Cameroon, the greater misfortune happened at the lake Agate. People can't help asking, is the murderer sleeping?
Unable to escape the French Open, the murderer was finally "arrested". But unexpectedly, the murderer turned out to be the well-known carbon dioxide gas. However, what is even more puzzling is why carbon dioxide is so rampant. Why do people and animals die?
Scientists have found that the delicate chemical balance makes the water in Lake Nios and agate lake a peculiar layer, and the deepest water is extremely rich in carbonate. However, this chemical equilibrium is not stable. Under the influence of the external environment, especially when the crustal activity is frequent, the layered lake will be disturbed, and the deep water rich in carbonate will rise and decompose rapidly under the sudden change of pressure and temperature, and the whole lake will become a huge soda bottle that suddenly opens. Although carbon dioxide itself is not toxic, it will be harmful to human body if it exceeds 0.2% in the air, and it will suffocate people and animals if it exceeds 1%. Therefore, a large amount of carbon dioxide is released and sinks, and disaster is inevitable.
However, this chemical balance in the lake is not unique. Scientists also found that the water in Lake kelton in the former Soviet Union was distributed in five layers, and the bottom layer was permeated with more worrying hydrogen sulfide. Then will the chemical balance existing in it be broken? Will hydrogen sulfide be converted into highly toxic hydrogen sulfide and then make waves? More importantly, how to nip in the bud and prevent tragedies from happening again? Nowadays, scientists are facing the challenge of new topics in environmental chemistry.
3 the secret of killing the dog hole
There is a strange cave somewhere in Italy. The man walked into the cave unscathed, and the dog walked in and died. Therefore, local residents call it the "Dog Killing Cave", and superstitious people also say that there is a kind of monster called "Dog Killing" in the cave.
In order to uncover the secret of the "Dog Slaughter Cave", a scientist named Paalmann came to this cave for a field trip. He searched everywhere in the cave, but never found any "dog killer". He saw many stalactites hanging upside down in caves, stalagmites clustered on the ground, and many stalagmites emerged from the wet ground. Through these phenomena and scientific reasoning, Paalmann finally solved the mystery.
It turns out that this cave composed of a large number of stalactites and stalagmites is a limestone cave. Here, a series of chemical reactions have been going on for many years: the main component of limestone is calcium carbonate, which is decomposed by heat in the deep underground to produce carbon dioxide gas;
CaCO3 high temperature CaCO3 CO2↑ write
The generated carbon dioxide reacts with calcium carbonate in groundwater and limestone to generate soluble calcium bicarbonate;
Calcium carbonate, carbon dioxide, calcium H2O
When groundwater containing calcium bicarbonate seeps out of the formation, due to the decrease of pressure, calcium bicarbonate decomposes and releases carbon dioxide, which escapes from the water;
Ca(HCO3)2 CaCO3 ↓ CO2 ↑ H2O
Because carbon dioxide is heavier than air, it gathers near the ground and forms a carbon dioxide layer with a certain height.
When people enter the hole, the carbon dioxide layer can only be submerged to the knees, and a small amount of carbon dioxide diffuses, and people only feel slightly uncomfortable. Dogs in low-lying areas were completely submerged in the carbon dioxide layer and died of suffocation due to lack of oxygen. This is the truth that killing dogs in a dog hole does not hurt people.
4. Self-report of fluorine
My name is fluorine, and there are 7 electrons in the outermost layer. Besides me, there are chlorine, bromine, iodine and arsenic similar to mine. They are all members of my family, and people call our big family a halogen family. In our big family, I am the younger brother.
Chemists discovered me at the beginning of the19th century and determined that I was an element. But my elemental state was not separated until the 1980s of 18. 1764 German chemist Magraff was the first to divide me into complex states, and the free state was put forward by French chemist Movado. The former is the reaction between fluorite and sulfuric acid, which is relatively easy. But freedom is not easy to prepare. Later, Movasan absorbed previous experience. He dissolved my compound, potassium hydrogen fluoride (KHF2), in anhydrous hydrofluoric acid and used it as electrolyte for electrolysis. After working continuously for two years, I was finally born in this world on June 26th, 1886.
I have yellow-green gas at room temperature. I am naughty and make trouble everywhere, so my brothers and sisters don't let me exist alone, and always let another person take care of me. I have a strong personality and always fight with others. I played with my favorite hydrogen and became inseparable friends as soon as we met. Brother hydrogen and I form white fog in the air, which is called hydrofluoric acid when dissolved in water. But when we were together, we also made trouble everywhere, turning all kinds of people's plants yellow and animals dead. Even the master showed no mercy. So when people extracted my hydrogen-containing compound from other substances, a sad thing happened. For example, two brothers Knox, an Irish scientist in 1836, were killed by me, and the other was forced to stop working. But I admire their spirit of not being afraid of death, which laid the foundation for future generations. They are martyrs who died heroically in the process of understanding the history of chemical elements and deserve to be remembered by future generations.
In the periodic table of elements, my extended family is located on the right side of the periodic table, which is the seventh main family and belongs to nonmetal. I am the most active in my family, so I can leave their compound instead of my brothers and sisters.
I was first used by the German artist Swanhard at 167 1. He found that the solution made by the reaction of my compound fluorite (CaF2) with sulfuric acid can describe glass.
I am one of the most widely distributed elements in nature, second only to chlorine in halogen family. Since people know my true colors, they have widely used me.
Adding my natural compound elements as solvents to molten ore can lower the melting point. My compound with hydrogen can be used to make plastics, rubber, medicine, fluoride such as sodium fluoride, which is an insecticide used to kill underground pests and can also extract uranium. With the development of science and human progress, people's understanding of me is further deepened. I hope my classmates can make friends with me, turn my disadvantages into advantages and further serve mankind.
5. Lime "family"
Lime is a common substance in people's lives. In the lime family, there are brothers and sisters named quicklime, hydrated lime, lime water, lime milk, alkali lime and so on. And their mother, whose name is limestone. Students who have just learned chemistry may be confused by their faces. Let me introduce them:
Limestone, born in the deep mountains, is a blue stone. Limestone mountains are generally beautiful. There are many limestone caves in Guilin, where many stalagmites and stalactites are formed. Limestone is hard, and it is often used in railway subgrade construction. The main chemical component of limestone is calcium carbonate (CaCO3), which is also the raw material of cement and other industries. Her sister, whose composition is the same as limestone, is called marble. She is clean and beautiful, and is a decorative material for high-grade buildings. Limestone is converted into quicklime by calcination.
The composition of quicklime is calcium oxide (CaO), which is white and blocky and has strong water absorption, and is often used as a desiccant. It reacts with water to become hydrated lime.
The component of hydrated lime is calcium hydroxide [Ca (OH) 2], a white powder with strong corrosiveness, so it is also called caustic calcium, which is mainly used as building materials, and the slurry for indoor walls and bricklaying cannot be separated from it. She is used to make bleaching powder in the chemical industry. Because she is digested with quicklime and water, it is also called hydrated lime.
Lime milk is turbid lime water, also called calcium hydroxide suspension, which is a mixture of solid and liquid. Commonly used are painting old walls, preparing Bordeaux mixture (adding copper sulfate) and stone sulfur mixture (adding sulfur) as pesticides to kill insects.
Limewater is a solution of calcium hydroxide. The supernatant after lime milk clarification (standing) is saturated lime water, which is very alkaline and is used to make rice tofu at home.
Alkaline lime is a mixture of calcium oxide and sodium hydroxide.
6. Chemical Lake
There are countless lakes, large and small, some are saltwater lakes, some are fresh water lakes, and all kinds. Some of these lakes are rich in special chemicals, forming chemical lakes.
Lake Mercury has a lake in the Hinton Mountains of the former Soviet Union. People will feel sick, dizzy and have difficulty breathing when they are 400-500 meters away from it. If they don't leave in time, they will suffocate. A large amount of mercury was once stored in the lake, and a large amount of mercury vapor was emitted. If people come into contact with animals for a long time, they will die of poisoning.
There is a lake in Sicily, Italy. There are two springs spewing out strong acid at the bottom of the lake, so the water in the whole lake has become extremely corrosive "acid water" with high concentration. This kind of lake with high acid concentration can kill all life. Some people call it a dead lake.
Alkali Lake There is a lake in the Urals of the former Soviet Union. The lake is salty. It turns out that some clothes containing alkali and sodium chloride in the water here can be washed very clean without detergent as long as they are soaked and rubbed in the water.
Salt Lake The Dead Sea in West Asia is the saltiest lake. The lake here contains 272 grams of salt per liter. Because the lake is salty and dense, people can be lifted up.
Lake Borax Lake In Chile, Lake Atsco is covered with large white ice floes, and the lake contains a lot of very useful borax [Na2B4 O5 (OH) 4 8H2O].
Fluorescent Lake has a "lake of fire" on the island of Bahamas in the Indian Islands in western Latin America. The lake sparkles like a flame when it burns. The water in this lake contains a lot of fluorescein. If you want to touch the lake, it will be "cremated" and splashed, which is caused by fluorescein.
7 Shenhuo and Chemistry
In 673, the Arab fleet invaded Constantinople, and the Greeks had only a few warships. The strength gap between the two sides is too big. In that kind of danger, who would have expected that it was not the friendly forces or the fleet that saved the Greeks, but their own chemical corps? It was a surprise fire in 2000!
I don't know which Greek architect likes to study alchemy, but he came across an incendiary agent that can catch fire on water. It was this incendiary agent that turned the waters around the Arabian fleet into a sea of fire, leaving the enemy powerless to fight back.
The Arab soldiers who escaped by luck said that the Greeks called "lightning" to burn the ship. Others said that the Greeks had mastered the "magic fire" and even the sea caught fire.
Since then, the Byzantine fleet has dominated the sea for centuries with "Shenhuo". They always win battles and are very proud. Europeans call this incendiary agent "Greek fire".
How many years passed before chemists uncovered the secret of the "Greek fire". It turns out that it is only composed of two common substances-lime and oil. Didn't you see the lime pool where eggs can be boiled on the construction site? When this combustion agent is used, quicklime releases enough heat when it meets water to ignite oil and gas, and the combustion agent will ignite and spread on the water surface.
When the Greeks used their "sacred fire" to show off in the Mediterranean, we in China invented an incendiary agent composed of saltpeter, sulfur Juan and charcoal more than 0/00 years ago, and used it to make fireworks, black powder and rockets.
Nowadays, black powder is no longer used in modern wars. However, do you know that this slender and soft fiber of cotton also contains an extremely dangerous characteristic? In the Chemistry Laboratory of Senior Three, after cotton is treated with the mixed solution of concentrated nitric acid and concentrated sulfuric acid, it will burn out as long as it is touched with a hot glass rod, and the famous smokeless flame is made of it. Nitrocellulose with high nitrogen content is called collodion in industry, and the volume of gas generated when the shell is filled with compacted collodion will increase by 12000 times.
Thousands of years of human civilization, almost every page shines with the brilliance of chemistry!