In a fire alarm, if we start with americium-241 which emits radiation at 370 kBq (as an example) what will have happened to the decay rate after 470 years (half life is 470 years). The amount of americium will be half, but does this mean that the radiation will also half, thus being 185 kBq?
In other words, does the rate at which radioactive particles are emitted also change with time?