1, we should pay attention to the study of basic knowledge, which is the guarantee to improve our ability. Learn chemical terms, such as element symbols, chemical formulas, chemical equations and basic concepts, and the properties of elements and compounds. Doing problems should be good at summarizing classified problems and solving problems. There are inherent laws between chemical knowledge. If you master the rules, you can control and remember knowledge. Such as the general law of valence, metal elements usually show positive valence, nonmetal elements usually show negative valence, the valence of simple elements is zero, and many elements have valence changes, and the valence States are different under different conditions.
2. Review in time after class and do your homework carefully, which is an important part of learning chemistry well. Review can be done after class, after week, unit review, chapter review and comprehensive review. Review methods include retelling, dictation, contact, etc. Only by reviewing many times can we firmly grasp the knowledge.
3. A "wrong question book", which records the wrong questions in exercises, homework and exams, analyzes the causes of the mistakes, and records the correct and good solutions. Another "good problem book" records some good problems, good problem-solving methods, problem-solving skills and problem-solving rules. Reading it before the exam can get twice the result with half the effort.
4, solid need a spoon or paper slot, one oblique two to send three vertical; It is best to use a block or tweezers, one horizontal and two vertical. The liquid should be put in a flask, labeled by hand, and then poured out. The reading should be flat with the section, with the head down low and the head down high. The dropper drips with a pinch head, and the vertical suspension is pollution-free, uneven and in good position. Don't forget to clean it after use. The balance of the tray should be flat and the screw should be centered; Put things left and right, and clamp the tweezers first big and then small; The test paper should be cut down first, and the glass rod is immersed in liquid for the best test effect. Wet the test paper first, stick it on a stick and lean against the air. The outer flame of the heating wine lamp is two-thirds of the boundary. Sulfuric acid is stirred in water and injected slowly to prevent boiling and splashing. In the experiment, the air tightness is checked first, and the cups and bottles are heated through the net. After drainage and gas collection, remove the conduit first, and then move the lamp.