Uknown Elements?
 

Ok, so i just found this forum because i was searching for an answer to my question. I cant say I really have that much knowledge of chemistry, but anyway.

I got into a discussion with a friend the other day, and I was pretty sure that I was right, but I would like to find out from someone who knows better.

we somehow got to the subject of science, specificaly chemical elements. He was saying that there are many basic elements that could exist on other planets or other places in space that we know nothing about. I on the other hand believe, as I have for awhile, that the periodic table is exceptionally complete, and that there aren't really any elements out there to be found that we dont know about. Of course there are those man made elements like 102, 103, 110-112, etc. But from what i understand, those are extremely unstable, and arent likely to be found in nature anywhere.

I have to admit that I could just be acting stuborn and am very wrong...this one friend is the one person that I dont like admiting being wrong to. So anyone that knows more on this subject, I would really appreciate knowing what is true, and maybe some places I could find some actuall evidence to back it up?

thanks in advance for any answers.

You are right, your friend is wrong. There is a limited number of known stable elements, any periodic table contains them all.

As I know such discussions you need some kind of proof :wink:

Atoms of any element when heated emit light of known wavelengths. Thus we can compare elements present on Earth with those present on Sun and on any other star, no matter how far it is. All spectral data known can be interpreted in terms of known elements - that confirms our knowledge is complete and there are no other elements in known observable universe.

Best,
Borek

thanks for the reply! I was pretty sure that I knew what I was talking about, and its very nice to know how to back it up.

Re: Uknown Elements?
 

Although the Russians keep trying.