In fact, I personally think that chemical physics in junior high school is not difficult to learn ... chemistry, chemical equations must be memorized. In fact, there are only a few commonly used, such as metathesis reaction, which are all regular. You should understand them well and do more exercises. If you do more, you will naturally understand the laws, chemical formulas and common ones ... You should remember that it is simple to understand pure substances and mixtures first, but it is more difficult for you to understand acids, bases and salts. Those reactions must be familiar. Those valences, such as ionic valences, should be memorized, and then the elements that need to be memorized in the periodic table should be memorized, which is basically enough. Science still needs more practice! Physics, circuit, parallel connection, series connection, do more, there are only a few formulas …P=UI U=R/I U=W/T, etc., so you should memorize them until you see that the topic can be transformed without confusion …