common experimental instruments and their use   i. classification of common instruments   generally, according to the main use of the instrument, the common chemical experimental instruments can be divided into the following 8 categories:   (i) measurement category  ...

  1 deep understanding of the great opportunities brought by the reform and development of basic education in the next 10 years   the outline of the national medium-and long-term education reform and development plan (hereinafter referred to as the outline) was revised and perfected last month...

  high school chemistry experiment poetry   1. the use of pallet balances   the dial of the screw code, the pointer ruler has a tray. adjust the screws up to balance, the matter code separation left and right side.   take the code need tweezers clip, first big after small r...

  use of chemical instruments and precautions: l. an instrument that can be heated   (l) a container used in a small amount of drugs, at room temperature or in a heating condition, for a small amount of reagent reaction, which can be used to make or collect a small amount of gas.  &ems...

  epoxy resin board:   1. the most common method is to clean the countertop with 70% concentrations of ethanol before and after work.   2. if it is only to remove the surface of the dirt, with a damp cloth can be used; if these dirty things are harder to wipe, it is recommended to ...