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.
Three other radon isotopes have a half-life of over an hour: 211 Rn, 210 Rn and 224 Rn. The 220 Rn isotope is a natural decay product of the most stable thorium isotope (232 Th), and is commonly referred to as thoron. It has a half-life of 55.6 seconds and also emits alpha radiation.hree other radon isotopes have a half-life of over an hour: 211 Rn, 210 Rn and 224 Rn. The 220 Rn isotope is a natural decay product of the most stable thorium isotope (232 Th), and is commonly referred to as thoron. It has a half-life of 55.6 seconds and also emits alpha radiation.