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.
radioactive isotope. n. An isotope having an unstable nucleus that decomposes spontaneously by emission of a nuclear electron or helium nucleus and radiation, thus achieving a stable nuclear composition. chemical element having the same atomic number as another (i.e. the same number of nuclear protons), but having a different atomic mass (i.e. a different number of nuclear neutrons). radioactive isotope. one having an unstable nucleus and which emits characteristic radiation during its decay to a stable form.