Half-Life
What is half-life?
A half-life is the amount of time it takes for approximately half of the atoms in a radioactive sample to undergo nuclear decay. A half-life is a probability, because we cannot know exactly when certain atoms will decay, only that it takes a certain amount of time for approximately half of the atoms to undergo decay. Different atoms have different half-lives depending on their stability. If an atom has a long half-life, it is considered to be more stable (less radioactive) than an atom with a short half-life.
What is the parent isotope?
The parent isotope is the original isotope that undergoes radioactive decay.
Protactinium-233 undergoes beta decay into uranium-233
Parent - protactinium-233
Daughter - uranium-233
What is the daughter isotope?
The daughter isotope is the decay product of a parent isotope, where the parent turns into a daughter isotope during nuclear decay.
Protactinium-233 undergoes beta decay into uranium-233
Parent - protactinium-233
Daughter - uranium-233
Is it possible to predict exactly when a specific atom of a radioisotope will undergo decay?
No, it is impossible to predict exactly when a specific atom will undergo decay. However, we can predict the probability of how long it takes for approximately half of the atoms in a given sample to undergo decay. This is the half-life.
Which uranium isotope is considered more radioactive?
Uranium-238 = 4.47 billion years
Uranium-235 = 0.704 billion years
Uranium-235 is more radioactive as the half-life is shorter.