Part 1 of Essay
is a substance whose form is dependent upon a great number of properties. It can be categorized under different types. Soda-lime is theleast expensive of the types for good reason. Lead is used most commonly as an art . Borosilicate has many advantageous properties. Aluminum silicate is not quite so comm ....

Part 2 of Essay
.... by modifying the composition, production techniques or both. represents a combination of properties that can not be separated, such as mechanical, chemical, optical and thermal properties. is an intriguing substance in the way that the moment you change the percentage of one of its components, the itself is different. (Education Dep. Properties: Chemical). Often, it can even be classified as a different type of . Commercial es are found in six basic categories, soda-lime , lead , borosilicate , alumi ....