Half-Life (Also seen in GCSE Physics 1)

Each radioactive isotopes has its own half-life. We already know that it is:

The time it takes for the number of atoms in a sample to drop to half of its original sample or

The time it takes for the activity of a substance to drop to half of its original activity

Half-Life is measured in seconds, s

The half life of a substance is linked to the decay constant.

If there is a high probability that a nucleus will decay ( = BIG) then it will not take long before half the sample has decayed to stability (half-life = short).

If there is a low probability that a nucleus will decay ( = small) then it will take a long time for half of the sample to have decayed (half-life = LONG).

where is the half life