Period 4 element be dangerous in large enough quantities due to its radioactivity. Nickel (Ni) is an element in period 4, between cobalt and copper. Nickel is rare in the Earth's crust, mainly due to the fact that it reacts with oxygen in the air, with most of the nickel on Earth coming from nickel iron meteorites. However, nickel is incredibly common in the Earth's core; along with iron it is one of the two main components. Nickel is an important component of stainless steel, and in many superalloys. Copper (Cu) is an element in period 4, between nickel and zinc. Copper is
CU-SeeMe in the Radvision Scopia product line. There is still a small but active community of users of the original CU-SeeMe releases. Although there have been no releases of software from the various incarnations of White Pine since roughly 2000, freeware alternatives are available for both the Windows and Macintosh platform. The CU-SeeMe name and legacy remains important for a number of reasons: CU-SeeMe CU-SeeMe (also written as CUseeMe or CUSeeMe depending on the source) is an Internet videoconferencing client. CU-SeeMe can make point to point video calls without a server or make multi-point calls through server software first called a