In a typical radioactive decay graph, the y-axis represents the number of radioactive atoms remaining, and the x-axis represents time. The graph depicts the decay of radioactive atoms over time.
The reason a radioactive decay graph never touches the x-axis is due to the probabilistic nature of radioactive decay. Each radioactive atom has a chance of decaying during a given time interval, but it is impossible to predict exactly when an individual atom will decay.
As time progresses, the number of radioactive atoms decreases as they decay. However, even if only a small number of atoms remain, there is still a finite probability that some of them will decay during the next time interval. This probability never reaches zero, which means there will always be some atoms remaining, no matter how small the quantity.
Therefore, in a radioactive decay graph, the curve representing the decay process approaches the x-axis asymptotically but never actually touches it. This indicates that the decay continues indefinitely, although the number of remaining radioactive atoms becomes increasingly small over time.