The children are in Zhenjiang Yangzhong Middle School, and it is difficult to give them some advice because the children in Grade Two have just come into contact with physics. You can only give children a small stove and ask for a tutor.
If children are interested in physics, it will be easier to learn!
My child just came into contact with chemistry in junior high school and studied for two days. I hope you can give me some advice. ① The reasons why parents communicate with chemistry teachers.
(2) Children should consult classmates and class representatives who are good at chemistry.
(3) Children should find a time to teach after class, so as not to disturb the teacher's rest.
(4) On weekends, please ask a chemistry tutor to let the children consolidate and improve.
Chemistry can't keep up, probably because children are not interested in it. Find some interesting chemical experiment videos for children to watch and enhance their interest.
6 change to liberal arts, etc. And avoid partiality.
The most important thing is to say it three times! Ask bravely if you don't understand! Ask bravely if you don't understand! Ask bravely if you don't understand! To solve the root cause! No one is born without learning.
My child has just entered the sixth grade of Chinese in Zhenjiang Yangzhong. He looks at pictures and writes poorly. I hope you can give me some advice. Don't rush to teach the children. First of all, you should know whether your child likes Chinese or not, and how he usually expresses himself.
You can cultivate children's ability in this respect at home, such as communicating with children more, reading an article every day, and then talking about some feelings after reading this article. Don't put too much pressure on children in the early stage, or focus on cultivating interest; 1, 2 months later, just write some feeling sentences slowly, without spaces, just a paragraph.
Finally, you can take your children to the library, book club, etc. Develop interest and practice slowly. It will be fine after a long time.
It's grade three now. Here are some suggestions for learning chemistry. I always find the chemical formula difficult to recite. Middle school chemistry is relatively simple and the most basic content. Junior high school chemistry should pay attention to accumulation, and the first thing is to master the most basic things. The most basic thing is the valence of common elements in element symbols. This is the basis for writing chemical formulas and reaction equations of various substances. Generally speaking, if you practice more, you will be handy. However, in the early stage of your study, I suggest that you can use various methods, including rote learning, to master these firmly. Many things, such as the valence of various elements, you don't understand why there are so many, but now junior high school doesn't need to know these things, just use them. If you are really interested in chemistry, inorganic chemistry at the university will tell you a lot.
I felt very tired when I first came into contact with chemistry in grade three. Can I make it? I am a college student, and I happen to tutor a junior three student. I hope I can give you some useful help, but I still have to learn by myself!
In fact, the most important thing in chemistry is to remember chemical equations, remember the chemical properties represented by each chapter, and learn to associate! This is the basic knowledge. I think the teacher will print out the chemical equations you have learned. You need to memorize them!
What I arranged for you is not divided according to the course. I think you'd better find the deficiency by doing the problem and then read the book and recite the knowledge points!
Do box table questions first, which can best examine the context of knowledge and your summary and understanding of knowledge points, find different unit questions to do, and the most important thing is to turn pages quickly. As long as you have perseverance, you will gain a lot. Stick your knowledge points in every question you do and find a notebook to write it down!
Second: do the calculation. The calculation problem is a problem that I will grade for you. As long as we find a knowledge point, we can solve the calculation problem in junior high school according to the relative molecular mass of the other two chemicals. What I ask you is to learn to explore the law and learn to recite the question!
Third, review the experiment. The key to the use of experimental instruments is to remember the precautions, the mistakes that are easy to occur in operation and the various uses of those commonly used instruments, such as the accelerated dissolution and drainage of glass rods. Secondly, do experimental questions, remember some conventional gas collectors and impurity collectors, and do more experimental design questions!
Fourth: it is better to consolidate the experimental part, or you need a notebook to record and remember those important things to review and consolidate! In addition, take the time to do a comprehensive review of the topic, then find the flaws in the review, and pay attention to the concept of time when doing the topic!
Fifth: you'd better browse the better review materials in chapter order (I believe the school will send them when you review), and keep the unfamiliar places in your notebook at any time!
Sixth: Take out the test paper that the teacher gave you, find the wrong questions to do, and improve efficiency, because this workload is big enough! Write down what you think is useful in your notebook!
Seventh: What the teacher sends you is the most useful. Do the whole set of questions when you have time and exercise your time concept!
The rest is to take out the things sorted in the notebook and recite them well! This is the case with education in China. It is not enough. If you work hard and have perseverance, you will definitely get 25 points!
Chemistry is actually not that difficult. I think he feels a little liberal, and he has a lot to recite, which determines that as long as you recite well, you must never give up! You have great potential in chemistry! I hope you get good grades in the senior high school entrance examination!
A lovely new-comer game. Is there a great god to give some advice? It should be friendly to newcomers. After all, you don't have to worry about losing your card when you experience the game. ...
But it is very unfriendly to office workers who play games with fragmented time.
For students who have more time (such as universities), it is quite reliable!
The child has just come into contact with chemistry and is a little at a loss. Which class should he apply for? Write down the following knowledge points first, and remember the top 20 of the periodic table of elements.
Six, the color of the material
Most solids are white, and most gases, liquids and solutions are colorless.
Black solids: charcoal, copper oxide, ferroferric oxide, manganese dioxide and iron powder.
Blue solids: copper sulfate crystals, copper chloride and copper nitrate, and their solutions are also blue.
Yellow solids: ferric chloride, ferric sulfate and ferric nitrate, and their solutions are also yellow.
Blue precipitate: copper hydroxide Cu(OH)2 is insoluble in water but soluble in acid.
Red-brown precipitate: iron hydroxide is insoluble in water and soluble in acid.
Sulfur is light yellow solid liquid oxygen, and solid oxygen is light blue.
Red solid: copper, iron oxide, red phosphorus and potassium permanganate: purple-black solid.
Light green: ferrous chloride, ferrous sulfate, ferrous nitrate and their solutions.
Green: basic copper carbonate (commonly known as copper rust)
Nine, the most in chemistry
Diamond is the hardest mineral in nature, and graphite is the softest mineral.
Oxygen is the most abundant (nonmetallic) element in the earth's crust, and aluminum is the most abundant metal element in the earth's crust.
Calculated by volume fraction, nitrogen (N2) is the most abundant component in the air.
The gas with the lowest density, the substance with the lowest relative molecular mass is hydrogen (H2), and the atom with the lowest relative atomic mass is hydrogen (H).
The oxides with the smallest relative molecular weight are the simplest organic water (H2O) and the smallest organic methane (CH4).
Among the active sequences of metals, potassium (K) is the most active and gold is the weakest.
The element that forms the most kinds of compounds is carbon (C) atom, which is the smallest particle in chemical desalination.
XI。 A typical solution to the problem
1. Solids separated by dissolution, filtration and crystallization must meet the following requirements: one solid is soluble and the other is insoluble, and the two substances will not react chemically after dissolution.
2.*** There is a problem: no two substances react in the solution, and the substances in the group can exist in the same solution. As long as any two substances in the group can react, the substances in the group cannot exist;
The existence of energy between ions must meet the following requirements: any combination of cations and anions will not produce precipitation, gas or water.
3. Inference breakthrough: ① Color (copper salt blue, iron salt yellow, colorless phenolphthalein turns red when dissolved in alkali)
② precipitate (AgCl BaSO4 is insoluble in acid, iron hydroxide is reddish brown, copper hydroxide is blue, and other precipitates are white.
If dilute nitric acid is added to the precipitate: the precipitate does not dissolve, there must be AgCl or BaSO4 in the precipitate; If the precipitate is completely dissolved, there must be no AgCl or baso4 in the precipitate; If the precipitate is partially dissolved, there must be one of AgCl or BaSO4 in the precipitate, and the other is soluble in dilute nitric acid.
③ Gas (gas is generated in the double decomposition reaction: acid and carbonate, and the metal before hydrogen reacts with acid to generate hydrogen gas with the lowest density in the metal activity order).
4. The reagent used to distinguish multiple substances at a time must meet the following requirements: each substance in the group has different phenomena after interacting with the reagent. There are several possibilities for selecting reagents:
① Purple litmus test solution can distinguish three kinds of solutions (such as HCl NaOH NaCl) at a time.
Sodium carbonate, potassium carbonate or hydrochloric acid and sulfuric acid produce precipitation, gas and other phenomena.
Write a reagent to distinguish the following groups of substances at the same time:
(1) Barium chloride, sulfuric acid and potassium sulfate solution: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
(3) barium nitrate, potassium carbonate, potassium nitrate solution _ _ _ _ (4) hydrochloric acid, sodium hydroxide solution, lime water _ _
(3) Write the reagents and reaction phenomena that distinguish the following groups of substances at one time with solutions of special colors such as ferric sulfate or copper sulfate:
Reagent phenomenon of distinguishing barium nitrate, sodium sulfate, barium hydroxide and sodium hydroxide
5. A method for identifying several substances only by the substances in this group without other reagents:
(1) Use solutions with special colors such as iron salts or copper salts in the group to gradually distinguish each substance, for example:
How to identify the following four solutions without other reagents: silver nitrate, potassium hydroxide, sodium chloride and ferric chloride?
(2) There is sodium carbonate or potassium carbonate solution in the group, and sodium carbonate or potassium carbonate reacts with other three substances, including precipitation, gas and another phenomenon. In the following groups of solutions, all substances in this group can be distinguished one by one by using only the substances in this group without using other reagents.
Twelve. Chemical names, common names and chemical formulas of substances
Mercury (mercury) mercury sulfur (sulfur) calcium oxide (quicklime) calcium oxide
Solid carbon dioxide (dry ice) CO2 iron oxide (the main component of rust) Fe2 O 3
Calcium carbonate (the main component of marble and limestone)
Basic copper carbonate (patina) Cu2 (OH)2 CO3
Sodium chloride (salt) sodium chloride methane (biogas) methane
Ethanol (alcohol) C2 H5 OH acetic acid (acetic acid) CH3 COOH
Sodium carbonate (soda ash) Na2 CO3 copper sulfate crystal (blue alum, bile alum) CuSO4? 5H2O
Sodium hydroxide (caustic soda, caustic soda, caustic soda) NaOH calcium hydroxide (hydrated lime, hydrated lime) Ca(OH)2
Water gas: a mixture of hydrogen and carbon monoxide; Explosive gas: a mixture of hydrogen and oxygen.
Thirteen, the chemical formula of the substance
Elemental substance: A pure substance composed of the same (or one) element.
1, simple metal (in order of metal activity from strong to weak)
Barium, potassium, calcium, sodium, magnesium, aluminum, zinc, iron, tin, lead, copper, mercury, silver, platinum and gold.
Ba, K, Ca, Na, Mg, Al, Zn, Fe, Sn, Pb, Cu, Hg, Ag and Pt.
The child has just come into contact with chemistry in the third grade, and he doesn't learn very well. Where is a good junior middle school remedial class in Taiyuan, it is best to have one-on-one classes. Good remedial classes are expensive, and representative national chain institutions such as Xueda Education and Longwen Education may not teach well. It is better to find an experienced tutor yourself.
How to learn chemistry when you are just exposed to it in grade three? Personally, I don't want to recite chemistry First of all, as a student who thinks chemistry is good, I have never recited chemistry from beginning to end. Even the periodic table uses more skilled natural memory. As a child in grade three, I was exposed to chemistry for the first time. First of all, we should start with interest. Once we become interested in chemistry and feel the charm and magic of chemistry, we will have a natural spirit of inquiry. Secondly, we should tell chemistry that chemistry is a discipline, but there must be certain laws and methods. Therefore, if you suddenly come into contact with new things, don't get angry and don't encourage them. Slowly, through perceptual knowledge, experimental intuitive understanding and teacher's teaching, I believe that learning chemistry well is completely no problem.
Author: Deng Zhengyang
Link: Hu Zhi. /Question /22 190 157/ Answer /20573737
Source: Zhihu.
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