Require Answer to fermi dotpoint 4 quanta 2 quarks! (1 Viewer)

[Ifrit]

Can someone please give me an answer to the dotpoint in the Quanta to Quarks Module:

* Descrive Fermi's initial experimental observation of nuclear fission.

note: im not looking for the anser to the other Fermi dotpoint about his demonstration of a controlled nuclear chain reaction.

Thanks!

 

[Constip8edSkunk]

havent got alot on this pt:/

..after discovery of neutrons, fermi began investigating reactions between the neutron and the nuclei of other elements. when he irradiated uranium, he found an unknown beta emitter is produced (prolly artificially transmutating neptunium). However, occasionally, especially when slowing the neutron down 2 thermal neutrons, he found that many daughter products were produced. (this coz only the fissile U-235 was only of minute concentration, though unknown to fermi) By chemical analysis, he found they were many different elements, but he failed to investigate them any further or identify these products....this was done later by hahn and straussman, and furthered by meitner and frish later on. (not sure of the spelling of any of the names)

 

[juber]

Originally posted by Ifrit
Can someone please give me an answer to the dotpoint in the Quanta to Quarks Module:

* Descrive Fermi's initial experimental observation of nuclear fission.

note: im not looking for the anser to the other Fermi dotpoint about his demonstration of a controlled nuclear chain reaction.

Thanks!

Lol! this point has been fucking with me for a few days!

I figured it out though. Heres my answer:

"Fermi hypothesized that it should be possible to split the atom into two atoms of roughly equal size. In aiming to experimentally show this, he bombarded a range of elements. When he got to bombarding Uranium, the heaviest known element, he found that he produced an isotope (went from uranium 238 -> uranium 239) which would the undergo beta decay to form the first tranuranic element. Whilst performing the experimental proceedure, he found that under conditions he would be producing a wider range of elements. Fermi had in fact caused the first fission.

The experiment was later revisted by otto hahn and fritz straussment who experimentally confirmed the discovery of the lighter elements of roughly equal size which would be known as nuclear fission"

In summary the main points are:

- theorised that fission was possible
- bombarded uranium and formed the first transuranic element
- repeating the experiment found that a wider range of elements were formed under certain conditions (causing fission)
- fission revisted by Hahn and Straussman and more accurately shown.


The problem with this point is that most of the textbooks deal with the fact that he produced the first transuranic element rather than the fact that he actually caused the fission which is what makes the point confusing. But yeah, the thing is that he kinda failed to investigate it so it was really hahn and straussment who experimentally observed it first, whereas fermi merely produced the results first (kinda like how hertz failed to investigate the photoelectric effect)

 

[~Dreamer]

hey, i agree, i never really understood that dot point - and text book rambles on about his life history - and not what he did exactly

 

[SmokedSalmon]

Here is my answer to the dot point if anyone is interested

Fermi was the first to realise the neutron's potential. In the 1930's he bombarded as many of known elements as possible with neutrons. In the majority of cases new isotopes were formed. Occassionally this new nucleus was radioactive and emitted a beta particle. When he reached Uranium (the heaviest known element) he was confuse dby the results. They believed that they had created Uranium-239 which would undergo beta decay to form an isotope of the element with atomic number 93. i.e. The first transuranic element. However, Fermi did not detect the nucleus of Barium that was created. This was then shown (by Hahn and Strassman) to be a result of splitting the nucleus of URanium 235 present in the sample. They had discoverd Nuclear Fiassion.