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.
The difference between fraternal and identical twins is that fraternal twins are two separate eggs fertilized by two separate sperm to form two separate embryos and then make two separate babies.Identical twins are formed when one fertilized egg divides into two separate embryos to make two babies.raternal, or dizygotic, twins happen when Mom releases two eggs (either at the same or different times during her cycle), and different sperm fertilize each egg. Fraternal twins share up to 50% of their genes, and are no more alike or different than any two siblings would be.