A question was originally put in the homework help forum "1 gramm radiates 3,7*10^10 alpha-particles in a second. Find out the half-life" At a glance it looks simple. You start with X number of AMU, it's radiating at a rate of Y, find out how long it takes to get to 0.5X; right? Then I thought about it a second time. Once 1 atom of this substance emits an alpha particle, that atom is no longer the same, so it doesn't have the same rate it had before. This would mean the overall decay rate is constantly changing. If you think back to radioactive decay graphs from school, things do not decay in straight lines. Decay is always, or usually, logarithmic. This problem was in the easy physics homework section, which would imply no calculus is involved. I can't figure out how this problem can be done without it.