A geiger counter registers a count rate of 4,000 counts per minute from sample of a radiosotope. twelveminutes later the count rate is 1000 counts per minute. what is the half-life of the radiosotope?
An accident in a laboratory results in a room beingcontaminated by a radiosotope with a half-life of 3 days. if the radiation is measured to be eight times the maximum permissible level, how much time must elapse before the room is safe toenter?