Article source: Hohhot Junior High School Chemistry (QQ1042290701) reproduced the source, thank you for your cooperation!
Methods of learning chemistry
1. Develop good study habits
Pre-study before class, listen carefully during class, take notes, review in time, complete homework on time, timely summary of knowledge and necessary exercises.
2. Emphasis on textbook knowledge
Text, pictures, activity research, family experiments, etc. in chemistry textbooks are basic chemistry knowledge and skills, which should be fully utilized in the learning process. Good textbook resources.
3. Emphasis on the memory of chemical terms
Accurately remember the elemental symbols in chemistry, the valence of common elements, the chemical formula of common substances, and some basic concepts and principles and understand their connotations.
4. Emphasis on experiment
Chemistry is an experimental-based natural science. To learn chemistry well, you must experiment with yourself, carefully observe and think about problems related to experiments.
5. Emphasis on the cultivation of self-learning ability
Master the scientific learning methods of induction, comparison, summarization, analysis, etc., and actively propose chemical-related problems and solve problems.
6. Timely training, learn scientific methods
Through the “less and fine” exercises and unit tests, feedback your knowledge of knowledge in a timely manner, and train yourself to analyze and solve problems. Ability to solve problems, learn to summarize the rules of solving problems, and master scientific and efficient learning methods.
The case of logical reasoning is an important method of chemical thinking. The following reasoning is reasonable:
A ion is a charged particle, so the charged particle must be an ion.
B acid must contain hydrogen, so the substance containing hydrogen must be Medium acid
C A substance burns in oxygen to form carbon dioxide and water, so the substance must contain carbon and hydrogen.
D alkali solution can make the colorless phenolphthalein solution red Therefore, it is necessary to make the colorless phenolphthalein solution red.
[analysis] Protons are positively charged, electrons are negatively charged, A error: sodium bicarbonate ( NaHCO3) contains hydrogen, which belongs to salt, does not belong to acid, B error; some salt solutions such as sodium carbonate solution can also make the colorless phenolphthalein solution red, D wrong.
The answer is: C