Electrum is a metal alloy mainly consisting of gold, silver and traces of some other metals. This naturally occurring alloy has a long history of being used for making coins, vessels and also for coatings. It was referred to as âgoldâ or âwhite goldâ by ancient Greeks.
In Interstitial defect, atom occupies the interstitial space of the lattice structure of solid crystal. In Substitutional defect, the foreign atom occupies only the lattice site of a crystalline solid. Interstitial defect may occur by the atoms of either same solid (called self-interstitial) or foreign material. Substitutional defect is always caused by foreign atoms.
An atrial septal defect is a birth defect of the heart in which there is a hole in the wall (septum) that divides the upper chambers of the heart (atria). A hole can vary in size and may close on its own or may require surgery.An atrial septal defect is one type of congenital heart defect.n atrial septal defect is a birth defect of the heart in which there is a hole in the wall (septum) that divides the upper chambers of the heart (atria). A hole can vary in size and may close on its own or may require surgery.