Suggest two ways on which we …

Materials are grouped together on the basis of similarities and differences in their properties. Materials are grouped together for convenience and to study their properties. Grouping materials saves our time, energy and makes our work easier. It helps us to find things easier than searching through a lot of stuff at once. This concept is used in data handling in mathematics. This all does not make any sense so in order to understand this easily and instead of wasting time and effort we group this data to understand it in a better way. Transparent objects allow light to pass through them. Examples of transparent objects are: Air, glass, pure water, some plastics etc. Materials like air, water, and clear glass are called transparent. Materials which have a shine are called as lustrous materials. Usually metals like gold,silver,copper etc. are lustrous.