The following are all junior high school chemistry contents.
You extract it according to your own needs. Just extract it according to your typesetting.
As for the content of painting, you should consider it yourself. It is a good choice to draw the structural formula of some substances. )
Chemistry is a science that studies the composition, structure, properties and changing laws of matter. First, the principle of medication 1, medication should be "three noes": you can't touch drugs directly with your hands, you can't put your nostrils to the mouth of the container to smell the smell of drugs, and you can't taste any drugs.
2. Pay attention to economy when taking medicine: take medicine in strict accordance with the dosage prescribed by the laboratory. If the dose is not specified, the minimum amount is usually taken, that is, 1-2mL of liquid, and the bottom of the test tube is covered with solids. 3. The leftover drugs should be "three noes": that is, don't put them back in the original bottle, don't throw them away at will, don't take them out of the laboratory, and put them in the designated container.
4. If the liquid medicine spills into your eyes during the experiment, wash it with water immediately. Second, the way to obtain solid drugs is 1. Bulk or dense solid particles are usually taken out with tweezers. Second, the key (or paper slot) is used for powdered or small granular drugs.
3. Used tweezers or keys should be wiped with clean paper immediately. Second, get the liquid medicine (stored in a narrow-mouth bottle) as 1, and get a small amount of liquid medicine-the dropper with rubber-tipped dropper to absorb the liquid medicine should be hung vertically above the instrument, and the liquid medicine should be dripped into the instrument to receive the liquid medicine, and the dropper containing the liquid medicine should not contact with the instrument wall; Do not put the dropper flat on the test bench or other places to avoid polluting the dropper; Do not suck other reagents with unwashed droppers (the droppers on the dropper bottle are not interchangeable and do not need to be cleaned). 2. When taking the test solution from the narrow bottle, remove the cork and put it on the table; When pouring liquid, make the label face the palm of your hand, and the bottle mouth is close to the test tube mouth or instrument mouth to prevent the residual liquid medicine in the bottle mouth from flowing down and corroding the label.
3, the use of measuring cylinder A, take a certain volume of liquid medicine can be measured by measuring cylinder. When reading, the measuring cylinder must be placed smoothly, and the line of sight should be flush with the lowest concave liquid level in the measuring cylinder.
The top reading is high and the bottom reading is low. B, measuring the volume of liquid: firstly, pour the liquid into the measuring cylinder until it approaches the required scale, and then drop it to the scale line with a dropper.
Note: The measuring cylinder is a kind of measuring instrument, which can only be used to measure liquids, not to store drugs for a long time, nor to be used as a container for reactions. It cannot be used to measure supercooled or overheated liquids, nor should it be heated.
C, reading, if you look up, reading is lower than the actual volume; Looking down, the reading is higher than the actual volume. Third, the use of alcohol lamp 1, alcohol lamp flame: divided into three layers: external flame, internal flame and flame core.
The outer flame temperature is the highest and the inner flame temperature is the lowest. When heating, the heating substance should be placed in the outer flame part. 2. Precautions for the use of alcohol lamps: a. The alcohol in alcohol lamps shall not exceed 2/3 of the volume; B, the alcohol lamp must be covered with a lamp cap after use, and cannot be blown out by mouth; C it is absolutely forbidden to add alcohol to the burning alcohol lamp; D it is absolutely forbidden to light another alcohol lamp with a burning alcohol lamp, so as not to cause a fire.
E, when not using alcohol lamp, cover the lamp holder to prevent alcohol volatilization. 3. Instruments that can be directly heated are: test tubes, evaporating dishes, burning spoons, crucibles, etc. The instruments that can be heated but must be covered with asbestos mesh are beakers and flasks; Instruments that cannot be heated are: measuring cylinder, glass rod and gas container.
4. When heating the medicine, first dry the instrument, preheat it, and then heat it under the medicine; When heating solid medicine, the medicine should be placed flat, and the mouth of the test tube should be slightly inclined downward to prevent water from flowing back into the test tube and breaking the test tube; When heating the liquid medicine, the volume of the liquid shall not exceed 1/3 of the volume of the test tube, and the test tube shall be tilted upward by 45, and the mouth of the test tube shall not face itself or others. 4. Washing instrument: 1. Brush with a tube brush. When brushing, the tube brush should rotate or move up and down, but the force should not be too great to prevent damage to the test tube. 2. The sign of the cleanliness of the instrument is that the water attached to the inner wall of the glass instrument has neither gathered into water droplets nor flowed down in strands.
Four. Activity exploration 1. Exploration of candles and their burning: P7-P9 2. A probe into the air inhaled and the gas exhaled by human body: P 10-P 12 VI. Characteristics of Green Chemistry: P6 Unit 2: Air around us. Fossil fuels: the impact of fossil fuels of coal, oil and natural gas on the air: air pollution caused by the combustion of coal and gasoline. Clean fuels: ethanol and natural gas. Fossil energy. Hydrogen energy 3. Solar energy. The development and utilization of nuclear energy can not only partially solve the problem of fossil energy depletion, but also reduce environmental pollution. Unit 8: metal and metal materials 1. The sequence of metal activity: K Ca Na Mg Al Zn Fe Sn Pb (H) Cu Hg Ag Pt Au, the activity of gold metal decreases in turn. 2. Metal material 1. Pure metal copper, iron, aluminum and titanium 2. Definition of alloy: some metals or nonmetals in metals can be heated to make alloys with metallic characteristics. 3. Common alloys: iron alloy, aluminum alloy and copper alloy.
3. Metal attribute 1. Physical characteristics: luster, electrical conductivity, thermal conductivity, ductility and flexibility. 2. Chemical properties: metal reacts with oxygen 4al+3o2 = = 2al2o3; 3Fe+2 O2 = = fe3o 4； 2mg+O2 = = 2 MgO； 2Cu+O2==2CuO metal reacts with acid mg+2hcl = = MgCl2+H2 = mg+H2SO4 = = MgSO4+H2 = 2al+6HCl = = 2alcl3+3H2 = 2al+3H2SO4 = = 2al2 (SO4). 3+3H2 ↑ Zn+2HCl = = ZnCl2+H2 ↑ Zn+2H2SO4 = = ZnSO4+H2 ↑ Fe+2HCl = = FeCl2+H2 ↑ Fe+H2SO4 = = = FeSO4+H2 ↑ metal reacts with solution 2Al+3CuSO4 = = Al (SO4)+ Iron smelting: 1. Raw materials: iron ore, coke, air and limestone. Principle: Fe2O3+3co = = 2fe |+3co3. Equipment: blast furnace 2. Corrosion and protection of metals: 1. The rust condition of iron changes chemically with oxygen and water vapor. 2. Recycling of metals; 3. Mining minerals in a planned and reasonable way; 4. Look for metal substitutes. It's simple. Take it.
By Sprite.
Design of chemical handwritten newspaper
Friend: I'll provide you with some information about chemical manuscripts. I hope it helps you. These contents need to be sorted out First, 1 is the most abundant chemical element, and the most abundant metal element in the earth's crust is aluminum.
2. Oxygen is the most abundant nonmetallic element in the earth's crust. The most abundant substance in the air is nitrogen.
The hardest substance in nature is diamond. 5. The simplest organic matter is methane.
6. The most active metal in the metal activity sequence table is potassium. 7. The oxide with the smallest relative molecular mass is water.
8. Under the same conditions, the gas with the lowest density is hydrogen. 9. The most conductive metal is silver.
10, and the atom with the smallest relative atomic mass is hydrogen. 1 1, and the metal with the smallest melting point is mercury.
12, the most abundant element in human body is oxygen. 13, the element that constitutes the most kinds of compounds is carbon.
14, the most widely used metal in daily life is iron. Two: other 1. The three kinds of particles that make up matter are molecules, atoms and ions.
2. Hydrogen, carbon monoxide and carbon, which are usually used to reduce copper oxide. 3. As a fuel, hydrogen has three advantages: rich resources and high calorific value, and the product after combustion is water that does not pollute the environment.
There are generally three kinds of particles that make up atoms: protons, neutrons and electrons. There are only three kinds of ferrous metals: iron, manganese and chromium.
6. Elements that make up a substance can be divided into three categories, namely (1) metallic elements, (2) nonmetallic elements and (3) rare gas elements. 7. There are three kinds of iron oxides, and their chemical formulas are (1)FeO, (2)Fe2O3 and (3) Fe3O4.
8. The characteristic of the solution is three (1) homogeneous; (2) stability; (3) mixture. 9. The chemical equation has three meanings: (1) indicates what substances participate in the reaction and what substances are generated as a result; (2) The particle number ratio of molecules or atoms between reactants and products; (3) Represents the mass ratio of each reactant and product.
Chemical equations have two principles: based on objective facts; Follow the law of conservation of mass. 10 pig iron is generally divided into white iron, gray iron and ductile iron.
Carbon steel can be divided into three types: high carbon steel, medium carbon steel and low carbon steel. 12. There are three kinds of iron ore commonly used in ironmaking: (1) hematite (mainly Fe2O3); (2) Magnetite (Fe3O4); (3) siderite (FeCO3).
There are mainly three kinds of steelmaking equipment: converter, electric furnace and open hearth furnace. 14. The three reaction conditions that are often related to temperature are ignition, heating and high temperature.
15. There are two ways to change saturated solution into unsaturated solution: (1) heating, (2) adding solvent; There are three methods to change unsaturated solution into saturated solution: cooling, adding solute and evaporating solvent at constant temperature. (Note: For substances whose solubility decreases with temperature, such as calcium hydroxide solution changes from saturated solution to unsaturated solution: cool and add solvent; There are three ways to change unsaturated solution into saturated solution: raising temperature, adding solute and evaporating solvent at constant temperature.
16. There are generally three methods to collect gas: drainage, upward evacuation and downward evacuation. 17, three main causes of water pollution: (1) waste residue, waste gas and waste water in industrial production; (2) Discharging domestic sewage at will; (3) Pesticides and fertilizers used in agricultural production flow into rivers with rainwater.
18, there are three commonly used fire extinguishers: foam extinguisher; Dry powder fire extinguisher; Liquid carbon dioxide fire extinguisher. 19. The change of solubility of solid substances with temperature can be divided into three categories: (1) The solubility of most solid substances increases with the increase of temperature; (2) The solubility of a few substances is little affected by temperature; (3) The solubility of a few substances decreases with the increase of temperature.
20.CO2 can put out fires for three reasons: it can't burn, it can't help combustion, and its density is higher than that of air. 2 1, simple substances can be divided into three categories: metallic simple substances; Non-metallic simple substance; Simple substance of rare gas.
22. The three most important fossil fuels in the world today are coal, oil and natural gas. 23. The three black oxides that should be remembered are copper oxide, manganese dioxide and ferroferric oxide.
24. Hydrogen and carbon have three similar chemical properties: stability at room temperature, flammability and reducibility. 25. There are three times of light blue in the textbook: (1) liquid oxygen is light blue (2) sulfur burns in the air with a weak light blue flame (3) hydrogen burns in the air with a light blue flame.
26. Three blue colors related to copper: (1) copper sulfate crystal; (2) copper hydroxide precipitation; (3) copper sulfate solution. 27. The filtration operation has "triple inclination": (1) The lower end of the funnel is close to the inner wall of the beaker; (2) the end of the glass rod gently leans against the third layer of filter paper; (3) The edge of the beaker containing the liquid to be filtered is close to the glass frame for drainage.
28.Kipp generator consists of three parts: spherical funnel, container and airway. 29. The flame of alcohol lamp is divided into three parts: external flame, internal flame and flame core, of which the external flame has the highest temperature.
30. There are three noes in taking and using drugs: (1) Don't touch drugs with your hands; (2) Don't put your nose to the mouth of the container to smell the smell of gas; (3) Do not taste medicine. 3 1. Write down the colors and states of the following substances: blue solid basic copper carbonate (copper rust): green solid black solid: carbon powder, copper oxide, manganese dioxide, ferroferric oxide white solid: anhydrous copper sulfate (CuSO4), potassium chlorate, potassium chloride, magnesium oxide, sodium chloride, calcium carbonate and sodium carbonate.
33. Gases containing diatomic molecules: H2, oxygen, N2, chlorine and dihydrogen fluoride. Which part of the atomic structure determines the following points: ① The types of elements are determined by the number of protons; ② The classification of elements is determined by the outermost electron number; ③ The chemical properties of elements are determined by the number of electrons in the outermost layer; ④ The valence of elements is determined by the outermost electron number; ⑤ Relative atomic weight is determined by proton number+. 35. Organic compounds studied: CH4 (methane), C2H5OH (alcohol, ethanol), CH3OH (methanol), CH3COOH (acetic acid, acetic acid) 36. Macroscopically and microscopically, the law of conservation of mass can be summarized as five invariants, two definite changes and one possible change: (1) Five invariants: cognition.
Living Materials and Chemical Manuscripts
Chemistry and Life Essay (1) Why do raw persimmons taste astringent? People born in the north or south will have such a life experience: persimmons that are already red as fire on persimmon trees can't be eaten yet.
At first taste, it is still very astringent. Is this persimmon not fully ripe? Yes, but if persimmons are fully ripe, it is not good for people to pick, transport and store them.
Therefore, people often pick the persimmon when it turns red, and put it for a while, and it becomes a sweet and fragrant persimmon. So, why does persimmon have astringency? It turns out that this is because raw persimmons contain tannin (also called tannic acid), which makes persimmons astringent.
In order to get rid of the astringency of raw persimmons, people have come up with many ways in their constant life practice. Some people cover persimmons layer by layer with straw or pine needles, or bury persimmons in leaves with pears. After a period of time, the astringency of persimmons is gone. Some people directly scald persimmons with hot water, and the astringency of persimmons is naturally removed.
Now people have adopted the "carbon dioxide deastringency method", which is actually a summary of people's past life experience. People seal persimmons in a room to increase the indoor carbon dioxide concentration and reduce the oxygen concentration.
In this way, persimmons can't breathe normally, but breathe in the absence of oxygen. In the case of anoxic breathing, organic substances such as acetaldehyde and acetone will be produced inside raw persimmon.
These organic substances can turn water-soluble tannins into water-insoluble substances, so persimmons are no longer astringent, but sweet and fragrant. If you also have a few raw persimmons that want to "get rid of astringency", you can put them in plastic bags and tie them tightly.
Generally, the astringency can be removed in a few days. How did the students from Far North get the golden bananas? They can also eat delicious, fragrant and sweet bananas in the south.
Do you know why? As we all know, bananas are a special product of the south. Born delicate, untouchable. If it is not done well, it will rot in batches, and raw bananas will not mature automatically. What can we do? Don't worry. First of all, bananas are easy to damage and rot when they are ripe. So in order to transport bananas from far away southern Xinjiang, the e-commerce database 1'(8.5). ",') *"-People can't wait until bananas are ripe, but harvest them when they are not ripe. At this time, the banana skin is green, and a lot of starch in the body has not been converted into glucose and fructose, so the "body plate" is very tough and doesn't care if it collides.
This kind of banana is convenient for long-distance transportation. The bananas delivered to the destination are still green skin and hard meat, and the taste is both astringent and not sweet. Of course, they cannot be sold in the market.
Not when it's mature. Of course, people will find a way.
The banana has been picked from the tree, and it has lost its ability to mature itself. So, people found a way.
They pumped gaseous ethylene (C2H4) into the warehouse where bananas were stored, which enhanced the activity of oxidoreductase in bananas and solidified water-soluble tannins. At the same time, chlorophyll in the peel disappeared, and blue-green bananas became popular in Huang Chengcheng.
The pulp also becomes soft and gives off a fragrant smell. Bananas are ripe! Ethylene can not only make bananas and other fruits mature, but also make rubber produce more rubber milk, and tobacco ripens early.
This is really a magical gas. Why is "bad fishing" sweet? Students living in the south must know what "fishing bad" is, and it also has a name called sweet wine.
Although it smells like wine, it is not wine. It is made of timid rice or indica rice.
As we all know, rice is the main food for our people. Rice contains about 7% protein, and the main nutrient is 77% starch.
These starches are the main source of human thermal energy. We cooked rice, made medicated wine (commonly known as distiller's yeast) while it was hot, and made wine at the table. After nearly a day of heat preservation, we opened it and found that the taste changed, sweet and mellow, and it was very delicious.
This is what the south calls sweet wine. Why does rice become sweet wine after adding wine and medicine? As we know, starch, glucose and other carbohydrates are all carbohydrates, and they are similar in molecular composition.
Starch molecules are composed of many small molecules of glucose. The medicated liquor contains amylase, which can promote starch hydrolysis and convert starch into sweet maltose. Amylase also exists in human saliva. When we chew rice in our mouth for a long time, we will feel sweet, which is the process of converting starch into maltose.
When making wine, maltose is converted into glucose by maltose invertase contained in medicinal liquor, and the other part is fermented into alcohol. In this way, the originally bland rice turned into a sweet liqueur.
(2) Stinky tofu is a kind of food that people like. "Smelling stinky and eating fragrant" is the unique flavor of stinky tofu.
Stinky tofu tastes better. Students who have never eaten stinky tofu can't imagine why such stinky tofu has so many diners. If you hold your nose and bite the bullet and try bravely, you won't ask why.
It turns out that stinky tofu stinks, but it is delicious. No wonder its smell can't stop. Stinky tofu is made by processing soybeans into tofu with less water content and then inoculating Mucor seeds for fermentation.
Stinky tofu is produced in summer, when the fermentation temperature is high and the protein in tofu is completely decomposed. The sulfur-containing amino acids decomposed by protein are further decomposed to produce a small amount of hydrogen sulfide gas.
Hydrogen sulfide has a pungent smell, so stinky tofu smells strong. And because protein in tofu is decomposed more thoroughly, stinky tofu contains a lot of amino acids.
Many amino acids taste delicious. For example, the ingredient of monosodium glutamate is an amino acid called glutamic acid. So stinky tofu tastes extremely delicious and smells abnormal.
Stinky tofu is a patented product of China! Many famous foods are related to stinky tofu. For example, fried stinky tofu is a particularly famous snack. The contest between yeast and yeast powder In our life, yeast or yeast powder is usually added to dough to make cakes and steamed bread.
Seeking writing materials for chemical tabloids
Primary pollutants are also called "primary pollutants".
Pollutants directly or indirectly discharged into the environment by pollution sources. Such as chemical poisons and viruses discharged into clean air and water.
It is the main source of environmental pollution. Secondary pollutants are also called "secondary pollutants".
Pollutants discharged by pollution sources (usually called "primary pollutants") evolve into new pollutants in the environment. It is often more harmful to the environment and human body.
For example, the sulfuric acid mist produced by the encounter between sulfur dioxide and water vapor in the atmosphere is ten times stronger than sulfur dioxide; When photochemical smog occurs, it will produce secondary pollutants such as ozone, formaldehyde and acrolein, which are harmful to animals, plants and building materials. [Air pollution] There are a lot of pollutants such as dust, smoke, gas, fog, odor, smoke or steam in the outdoor atmosphere, and their characteristics and duration are enough to endanger human health or the lives of animals and plants.
Air pollution When the content of some substances in the air exceeds the normal content, it will harm animals and plants and affect their survival. The normal contents of C0, NH3, SO2, H2S, Cl2, O3 and NO2 in the atmosphere are all below a few parts per million, which has no obvious adverse effects on animals and plants.
However, since the19th century, due to the development of industry and transportation, these substances have been discharged into the atmosphere in large quantities, which has made air pollution increasingly serious, affecting the life activities of animals and plants and even human health. Some sources of pollutants come from nature (such as volcanic ash erupted by volcanoes), and some come from human activities, among which the exhaust gas produced by industry and transportation is the main pollution source.
Can be converted into water pollution and soil pollution. The phenomenon that radioactive substances pollute the environment is that the main pollutants are emissions from nuclear industry enterprises, radioactive fallout from nuclear tests, natural cosmic rays, radioactive deposits and natural radioisotopes.
It can harm human body through food chain or directly. Heavy metal pollution Environmental pollution caused by heavy metals or their compounds.
It is mainly caused by human factors such as mining, waste gas emission, sewage irrigation and the use of heavy metal products. For example, Minamata disease and pain in Japan are caused by mercury pollution and cadmium pollution respectively.
The degree of harm depends on the concentration and chemical forms of heavy metals in the environment, food and organisms. Air pollution caused by harmful gases emitted by automobiles.
The main harmful gases are carbon monoxide, nitrogen oxides, hydrocarbons and sulfur dioxide. Will cause photochemical smog and so on.
Due to the variety of gasoline, vehicle load, engine performance, road conditions, meteorological conditions and other factors, its quantity and types are different. Because the exhaust height of automobile is in the human breathing zone, exhaust pollution is very harmful to human health.
Radio frequency pollution Environmental pollution caused by radio frequency electromagnetic radiation (emission frequency is 3 kHz to 3* 105 MHz). Common pollution sources are high-altitude TV transmission towers, medium-short wave and microwave transmission equipment, high-frequency heating equipment and short-wave or ultrashort wave physiotherapy machines.
Soil pollution is a phenomenon that the soil quality deteriorates due to pollution. Pollutants mainly come from sewage irrigation, pesticide application, fertilization, waste stacking (or landfill) and atmospheric deposition.
It not only hinders the development of agriculture, forestry, fishery and animal husbandry, but also affects human health. White pollution The so-called "white pollution" is an image title for people to pollute the environment by plastic waste.
It refers to the phenomenon that all kinds of living plastic products made of polystyrene, polypropylene, polyvinyl chloride and other polymer compounds are discarded as solid waste after use, which is difficult to degrade because of littering at will, resulting in serious pollution of the urban environment. Water pollution Water pollution affects industrial production, increases equipment corrosion, affects product quality, and even makes production impossible.
Water pollution affects people's lives, destroys the ecology, and directly harms people's health, which is very harmful, especially the foam pollution. Environmental pollution: (environmental pollution) refers to the phenomenon that human activities change environmental elements or their state, worsen environmental quality, disturb and destroy the stability of ecological system and the normal living conditions of human beings.
In short, the phenomenon that the environment has changed its original nature or state due to human activities is called environmental pollution. For example, air pollution, water quality deterioration, waste accumulation, noise, vibration, odor and other damage to the environment are all environmental pollution.
Due to environmental pollution, the sunshine is weakened, the climate is abnormal, Shan Ye is barren, soil desertification, salinization, grassland degradation, soil erosion, frequent natural disasters and extinction of biological species. The essence of environmental pollution is that human activities discharge a lot of pollutants into the environment, which affects its self-purification ability and reduces the function of the ecosystem.
Description: Nature (environment) itself has certain self-purification ability. When the environment is destroyed and cannot be cleaned and repaired by itself, it will cause environmental pollution.
Beware of chemical pollution endangering food safety. There are many hazards caused by environmental pollution, among which environmental pollution of food is directly related to human health. To understand the problem of food pollution, let's listen to the opinions of experts. What does food pollution mean? Food pollution refers to substances unintentionally added to food during production (including crop planting, animal feeding and veterinary treatment), processing, packaging, storage and transportation, including environmental pollution and production and processing (such as mycotoxins).
Among them, the potential food-borne hazards caused by chronic long-term intake of chemical organic pollutants have become the focus of attention, including pesticide residues, veterinary drug residues, mycotoxins, some carcinogens and mutagens (such as nitrosamines) formed in food processing, and industrial pollutants, such as well-known dioxins. What kind of pollution is mankind facing? In the "hormone ocean", the biggest influence is the accumulation of chemical impurities such as pesticides and dioxins.
These substances have the highest concentration in fish, and they flow into the ocean with the rain, and are finally enriched in the fish in the upper ocean in the food chain of the big fish eat small fish. If people eat such a big fish, these chemicals will produce a greater concentration in the human body, which is harmful to human health. Wu Yongning introduced that in recent years, the use of pesticides such as pesticides and herbicides in China has also increased. Both synthetic and natural pesticides (including metabolites) are potentially harmful to human health, which can lead to death in severe cases.
These.
Chemical handwritten newspaper
Let me give you some advice. It is estimated that it will take me two hours to finish typing for you. First, introduce their positions in the periodic table of elements. Second, their electronic structure diagrams (protons, neutrons, electrons). Third, the gain and loss of electrons. Fourth, the valence, oxidizing power and reducibility that each can have. Fifth, the acid strength of the hydrate corresponding to the oxide with the highest valence. Sixth, how do they exist in nature? Seventh, some special reactions. Eighth, the relevant materials in chemistry books or exams, especially the more novel the better. For example, in the exam, you will often encounter something related to life and technology.
Everything related to it can be written down. The layout will be designed by yourself. I believe that if you finish this homework carefully, your chemistry score will advance by leaps and bounds, provided that you finish it carefully and don't be lazy.