The cost of mailing a first-class letter within Canada went up to 85 cents today â a 35 per cent jump from the 63 cents it cost yesterday.But the 85-cent rate is only available if stamps are purchased in a pack. If you want to buy just one stamp, it will cost $1.he cost of mailing a first-class letter within Canada went up to 85 cents today â a 35 per cent jump from the 63 cents it cost yesterday. But the 85-cent rate is only available if stamps are purchased in a pack.
uranium-235 atom absorbs a bombarding neutron, causing its nucleus to split apart into two atoms of lighter mass. At the same time, the fission reaction releases thermal and radiant energy, as well as releasing more neutrons. The newly released neutrons go on to bombard other uranium atoms, and the process repeats itself over and over.
Uranium decays slowly by emitting an alpha particle. The half-life of uranium-238 is about 4.47 billion years and that of uranium-235 is 704 million years, making them useful in dating the age of the Earth.