: 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.
A full sized CD/DVD label measures approximately at the disc's 4.65 diameter with a 40mm, 22mm or 17mm diameter hole cut from the center. Though smaller in size, business card CDs and DVDs as well as mini CDs and DVDs maintain the 40mm, 22mm and 17mm center holes, however their actual disc dimensions are less uniform. A 40mm, 22mm and 17mm center-holed mini CD or DVD will have a label with a diameter of 3.0625.