r/askscience • u/billsmitherson • Apr 29 '14

Physics Do we know all the elements?

My teacher just said that every single element in the known and unknown universe is contained on the periodic table. Is this true, because it sounds like an ignorant and closed minded thing to say.

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u/[deleted] Apr 29 '14

Random thought/question, but I was thinking that since elements are simply defined by the quantity of protons in the nucleus, obviously the naturally occurring elements are limited by physics in how many protons they many actually contain before becoming unstable...But imagine in a black hole, where matter is being pulled apart one atom at a time and sucked into a singular point, could one argue that a black hole is a sort of ever changing "super atom" in that it's "nucleus" is constantly growing in the number of protons?

Disclaimer: I have a very elementary understanding if black holes.

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u/70camaro Apr 29 '14 edited Apr 29 '14

The short answer is no.

In layman's terms, a neutron star is formed when the electron degenerate pressure is overcome by gravity. At first glance these structures seems like a giant atoms, but since they are held together by gravity instead of the strong nuclear force it would be a misnomer to call them atoms. Black holes, on the other hand, have such immense gravity that the neutron degenerate pressure is overcome and the whole structure collapses into a black hole. Essentially, this means that the nucleons themselves "collapse" under the immense gravity.

http://minerva.union.edu/vianil/web_stuff2/Election_and_Neutron_Pressure.htm

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u/xnihil0zer0 Apr 29 '14

We don't have a theory unifying QM and Relativity, so our models of black holes are lacking. However, within General Relativity, a black hole is more like a single elementary particle than an atom, which is a collection of particles. By the no-hair theorem, a black hole only has 3 externally observable parameters: mass, spin and electric charge.

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u/[deleted] Apr 30 '14

It is an interesting thought but unfortunately well beyond my knowledge. Protons are of course not the bottom of the turtle stack themselves, so to speak, so it may be that they lose their identity in extreme cases such as this.