As radium is disintegrated, what happens to its half life?

Answer 1

The half-life of the isotope does not change -- it is a characteristic property of that element and isotope.

However, as the radium decays, it becomes other elements, some of which may have shorter half-lives, some of them longer half-lives. So the radioactivity of your sample changes over time, as more and more of the sample becomes other isotopes. For example:

Radium-226 emits an alpha particle (half-life 1599 years) to become Radon-222.

Radon-222 emits an alpha particle (half-life 3.8 days) to become Polonium-218.

Polonium-218 emits an alpha particle (half-life 3.0 minutes) to become Lead-214.

Lead-214 emits a beta particle (half-life 26.9 minutes) to become Bismuth-214.

Bismuth-214 emits a beta particle (half-life 19.7 minutes) to become Polonium-214.

Polonium-214 emits an alpha particle (half-life 164 microseconds) to become Lead-210.

And so forth.

Answer 2

As radium decays, it's half-life stays the same, but the amount of radium that decomposes will decrease:

1st HL -> 1/2 amt
2nd HL -> 1/4 amt
3rd HL -> 1/8 amt
4th HL -> 1/16 amt
etc.

Answer 3

No matter how much radium you have, its half life remains constant