Physical change, a change that occurs physically, and can also be seen physically. But chemically, it's a change that occurs within the chemical, and most likely not be seen within the eyes, but, has a different charater afterward.
<span>Safety glasses are to be worn whenever working with acids, bases, or any flammable materials. Let the instructor know immediately about any glassware breakage or chemical spills that may occur so that proper cleanup procedures can be instituted.Use pipet fillers whenever pipeting any fluid.Whenever working with acids or bases, have the chemicals available at your work station, do not carry pipets with fluid across the room.When diluting acids, pour the acid into the water, NOT water into acid as this may cause spattering of the acid.When acid is mixed with another reagent, an exothermic reaction may occur which heats up the container, This is natural, so do not panic and spill contents.All volatile materials must be handled in a hood with the exhaust fan on.When refluxing any solutions, perform this operation under a hood, and use boiling beads in the reflux vessel to prevent any excessive "bumping" and possible glass breakage.Use heat-resistant gloves and/or tongs when handling hot glassware, chinaware, etc.Use plastic gloves when handling any hazardous materials to prevent skin contact.Label and date all chemical mixtures that are made up and kept for future use.Do not store basic solutions in glass containers with glass stoppers, use plastic or rubber stoppers.Dispose of all used solutions in an approved manner as directed by the instructor.Empty all used inoculated bacteriological media from test tubes or dishes into a designated container so that it may be sterilized before disposal.Before leaving, turn off all power and heat to the apparatus you have used, or place in the standby mode.Clean all spatulas, glassware, and dishes after use and before storage to prevent contamination.<span>Return all chemicals you are using to their proper storage space.Be familiar with the use of the eye-wash, the laboratory shower (if equipped), and the first-aid kit if they are needed at any time.</span></span>
Low melting point
Low boiling point
Electric conductor
Atomic weights are weighted averages calculated by multiplying the relative abundance of each isotope by its atomic mass and then summing up all the products.
