Why do chemists classify matter? Well classifying matter is very important in chemisty. See chemists want to know what things are made of and what type of things they are. They also like to mix different things together. So they need to know what two or more peices of matter don't like to be created. If they didn't know what kinds of matter don't mix well, it could be very dangerous. Classifying matter isn't very hard it is actually quite simple. I'm going to refer to the classification pyrimid. This is how the pyrimid is set up. At the top it has materials or matter. Then to the lower left and right it has homogeneous matterials and heterogeneous matterials. Below the heterogeneous materials it just classifies as an heterogeneous mixture due to it has more than one piece of matter in the material. Now under homogeneous material you have a choice it's either a pure substance which is ususally solid, or a homogeneous mixture (solution). Usually solutions end in ite, ate, ide, etc. A pure substance is usually solid. Under that it is then classified as an element or a compound. How do you know if it's an element? Well look at the periodic table of elements if its on there then it's an element. How do you know if its a compound? Well a compound is made up of two or more elements. So look at the name for example NH3 then it is a compound because it has a nitrogen molecule and 3 hydrogen molecules. Science changes everyday and without our current knowledge of the elements and classifing matter then who knows where we'd be.