This is a list of seasons of the National Hockey League (NHL), a professional ice hockey league, since its inception in 1917. The list also includes the seasons of the National Hockey Association (NHA), the predecessor organization of the NHL, which had several teams that would continue play in the NHL.he NHL continued the split-season and playoff format upon the winding up of the NHA organization. Except for the 1919â20 season, where there was no playoff because Ottawa won both halves of the season, the champion of the NHL has been the playoff champion.
The radioactive half-life for a given radioisotope is the time for half the radioactive nuclei in any sample to undergo radioactive decay. After two half-lives, there will be one fourth the original sample, after three half-lives one eight the original sample, and so forth. More on half-life discussion.
Radioactive isotopes, also called radioisotopes, are atoms with a different number of neutrons than is usual, making them unstable.A radioisotope's nucleus decays, emitting alpha, beta and gamma rays until the isotope reaches stability.Once itâs stable, the isotope may become another element entirely, such as when uranium decays into lead.ignificance. Radioactive isotopes are useful because they produce alpha, beta and gamma rays. The radiationâs penetrating power depends on its energy, particle mass, and the objectâs density. These properties lead to many practical applications in science, medicine and industry.