# Half-Life Period

1. Nov 19, 2009

### Intelligent-E

Anyone with the same experience?
we are going through this on the laboratory, we quiet dont know how to treat it but I want to be the first to figure it out...
I know what it is but we need to solve how to make it stay on a normal radioactive rate before it goes critical (acourding to the drill of course).

THX

2. Nov 19, 2009

### mathman

Try to clarify what you are concerned about. You make references to "this" and "it", without explaining what they are.

3. Nov 19, 2009

### Intelligent-E

Half-life is the period of time, for a substance undergoing decay, to decrease by half. The name originally was used to describe a characteristic of unstable atoms (radioactive decay), but may apply to any quantity which follows a set-rate decay.

The original term, dating to 1907, was "half-life period", which was later shortened to "half-life" sometime in the early 1950s.[1]

Half-lives are very often used to describe quantities undergoing exponential decay—for example radioactive decay—where the half-life is constant over the whole life of the decay, and is a characteristic unit (a natural unit of scale) for the exponential decay equation. However, a half-life can also be defined for non-exponential decay processes, although in these cases the half-life varies throughout the decay process. For a general introduction and description of exponential decay, see the article exponential decay. For a general introduction and description of non-exponential decay, see the article rate law.

The converse of half-life is doubling time.

The table at right shows the reduction of a quantity in terms of the number of half-lives elapsed

4. Nov 19, 2009

### Staff: Mentor

Cutting and pasting that information is not helping us. And it may violate copyright law, depending on where you got it. In order to copy and paste information like that, you should include a link to where you got it from.