Junior high school chemistry summary !!! 1. chemistry is an experiment-based natural science that studies the composition, structure, nature and change laws of substances.What physics and chemistry have in common: natural science based on experiments.2. the fundamental difference between chemical change and physical change is whether there are any new substances.Some phenomena such as heat release, light emission, discoloration, gas release and precipitation occur in chemical changes.3. physical properties--State, odor, melting point, boiling point, hardness, density, extensibility, solubility, volatility, conductivity, adsorption, etc.4. chemical properties--Oxidation, reduction, metal activity, activity, stability, corrosiveness, toxicity, etc.5. after heati
Front water purifier, Haier and 3 M, is the difference between these two brands big? The difference is not big. is there only one pp cotton for the water purifier? Depending on the accuracy of the filter (5 microns and 1 micron), there are 90 grams in weight, 120 grams and 150 grams. Among them, the filtering accuracy is 1 micron and the weight is 150 grams! It's all right. 3MBSF1-100 looks like a high-end atmosphere, and Haier's is also good.
Design a set of reverse osmosis operation plan 10 You need to specify,What type of reverse osmosis system is needed.Because there are many kinds of reverse osmosis membrane systems,There is a pure water reverse osmosis system,Ultra-pure water reverse osmosis system,Water reuse system, etc,Different RO systems, the design will be different.Under normal circumstances,