Many middle school students will soon be exposed to a brand new subject, chemistry. Chemistry has many concepts, symbols, experiments and calculations. So what should I pay attention to when learning chemistry?
- Pay attention to basic knowledge The structure of chemical knowledge has some similarities with English. In the process of learning English, we know that to understand the meaning of sentences, we must master the words, and to master the words, we must master the letters and phonetic symbols. To use an inappropriate analogy: in chemical knowledge, "sentence" means "chemical formula", "letter" means " element symbol ", and "phonetic symbol" means " valence ". These are the basic knowledge that must be mastered proficiently to learn chemistry. Mastering them will lay a good foundation for learning elemental compounds, acids, bases, and salts in the future.
- Pay attention to method and memory. When we are new to chemistry, there is a lot of knowledge to remember. Therefore, only by mastering the memory method can you get twice the result with half the effort and improve learning efficiency. Here are some memory methods.
1. Repetition is the basic method of memory Repetitive memory of some chemical concepts, such as element symbols, chemical formulas, and some definitions, is the most basic method of effective memory.
2. Understanding is the premise of memory Understanding is not only answering "what" to a question, but also answering "why". For example, after understanding the structure of a substance, we should also understand the meaning of this structure. In this way, it is easy to remember the nature of the substance, and then remember the preparation and use of the substance. Therefore, we should try our best to remember any questions on the basis of understanding. For example, the valences of potassium oxygen, calcium, barium, magnesium and zinc, aluminum, silicon, sulfur, 246, nitrogen and phosphorus are three or five, the valences of carbon and four are iron, and the valences of copper and mercury are one or two". For example, the experimental points of hydrogen reduction copper oxide : first pass in hydrogen gas, then light up, stop heating, and then stop hydrogen gas.
Third, we must pay attention to the experiment and do the experiment well is the basis of learning chemistry.So take it seriously. Before each experiment, we must first figure out what the purpose of the experiment is, and then keep in mind the main points of the experimental device, and follow the operating steps carefully. Secondly, we must learn to observe the experiment, pay attention to the state of the reactants, the color state of the product, the reaction conditions, the phenomena that occur during the reaction... Only in this way can we make correct conclusions. For example, when doing magnesium combustion experiments, not only should the dazzling white light and the phenomenon of dissipating a lot of heat be observed, but also the white solid produced by the combustion of magnesium. Because this white solid is magnesium oxide , unlike magnesium, the combustion of magnesium is a chemical change. In addition, it is important to keep a record of the experiment and write a report after the experiment is over.
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