the Elements

[YT2095]

I realise that Hydrogen has been around nearly since the very beginning, and the elements up to Iron are all made in stars, and elements Past Iron are Super Nova made.

 

does that include the radioactive Isotopes, or were they made some other way?

[Klaynos]

Helium, and deuterium are also from the early universe, everything else is from stars fusion (up to Iron) and pas that supernovae including radioactive isotopes.

[YT2095]

so when the iron core collapses (say in a class A1 super nova) and then "detonates", that shockwave makes heavier elements and ultimately blows the whole thing apart.

 

now I`m aware of Decay chains leading to daughter products etc... but when you have relatively short halflives even for what We consider to be Long in time, are there any elements that are decaying that are Still a direct result of a supernova as opposed to a Decay product?

 

I expect Bismuth would be one one for sure.

[Klaynos]

supernovae produce massive amounts of different elements/isotopes some of which have halflives which are longer than the universe has been in existance and some on the order of nanoseconds, so yes there are still supernovae caused isotopes on earth... anything with a halflife of the order 2x the age of the sun would probably be enough for the cloud to spread out and form new stars (the sun) so they'd still be 50x of that left... I suspect if you have a look around you can find some spectral emission data from observed supernovae clouds like SN 1604

[YT2095]

so Technically I can hold a lump of Th or U for instance, and say that it`s still "Hot" from the Supernova, and be correct?

[swansont]

Anything with a half-life longer than 100 million years or so could be a remnant. Of course if the half life is 100 million years, the abundance will be tiny, but as it gets longer than that you will start having the possibility of macroscopic amounts. If it's in a decay chain with a long half-life, you don't know if it was from the supernova or the decay.

 

Other candidates would be K-40 and Rb-87. Those are used in radiometric dating.

[YT2095]

so each decay such a material does, has been waiting since it was inside a Star to get out, that is Sooo Cool!

 

it put`s the word "Antique" to shame

 

I find it Equally fascinating that Life as we know it when broken down to bare chemicals, is Also majority Element 26 and lower in composition, it May be pure coincidence sure, but with the exception of a few such as Cobalt Copper Zinc and Iodine (maybe micro micro trace of others), it`s seems to be almost without exception.

[Mr Skeptic]

Some radioisotopes, like carbon-14, are made by other methods (in the case of C-14, cosmic rays + nitrogen).