: an isomer that is a stereoisomer of a compound having two or more chiral centers and that is not a mirror image of another stereoisomer of the same compound â
A compact disc is a deceptively simple looking device considering the technology required to make it. 1  CDs consist of three layers of materials: 2  A base layer made of a polycarbonate plastic. 3  A thin layer of aluminum coating over the polycarbonate plastic. 4  A clear protective acrylic coating over the aluminum layer.
The liner has five layers made of different kinds of materials: 1  The bottom layer next to the earth is made of at least two feet of clay that has been pounded until it is very compact. 2  Next is a layer of strong, flexible, very thick plastic, called high density polyethylene (HDPE).