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It gets better. You only appreciate just how well Wikipedia works (sometimes) in comparison to the others when you look at just how much of a mess the "viable and credible alternatives to Wikipedia" make of things. Just hit Random Page on Citizendium a few times and compare the reality of what it brings up to all Larry's "expert oversight" talk.
It gets better. You only appreciate just how well Wikipedia works (sometimes) in comparison to the others when you look at just how much of a mess the "viable and credible alternatives to Wikipedia" make of things. Just hit Random Page on Citizendium a few times and compare the reality of what it brings up to all Larry's "expert oversight" talk.
Well, I just had to go and look at the article on atoms, after the discussion of the Wiki article here, which I think was just plain mean and ignorant.
![hrmph.gif](http://wikipediareview.com/smilys0b23ax56/default/hrmph.gif)
In Citizendium's offering on Atom I ran across this gem:
QUOTE(Citizendium article on Atom)
In 1913 Niels Bohr used the Schrödinger equation to produce the first quantum mechanical model of an atom. He resolved the difficulties of Rutherford's model by making the non-classical assumption that there were only certain specific energy states allowed for these electrons. Bohr conjectured that the angular momentum of each electron was constrained to be an integer times Planck's constant divided by 2π, . Since, electrons could now only change energies between these accepted states, the discrete spectral lines could be explained by photons of equal value to the energy change between the acceptable states.
Bohr was only able to explicitly solve the Schrödinger equation for electrons orbits the hydrogen atom, though he conjectured that larger atoms would have a similar structure.
.Bohr was only able to explicitly solve the Schrödinger equation for electrons orbits the hydrogen atom, though he conjectured that larger atoms would have a similar structure.
So that's the effect of expertise, eh? FYI, the Schrödinger equation was invented in late 1925 and published in 1926, more than a dozen years after Bohr conjectured his way through his own primitive atomic model of 1913. Bohr's model is the beginning of the old quantum mechanics-- mostly wrong, but at least getting there. Heisenburg and Schrödinger are the beginning of the real and modern version of the theory. The Schrödinger wave equation makes use of the insight of de Broglie that there are waves associated with material particles. In 1913 nobody had a hint of this, including Bohr. So the history is completely wrong. The only equations Bohr solved were his own.
[re-edit: the potassium-40 "error" was actually a due to a misreading of beta+ as beta- It seems to be okay after all]
Argghh, another boner:
QUOTE(Citizendium Atomic Number)
In 1911 Ernest Rutherford discovered that atoms have a heavy, small, positively charged pit, which he called the nucleus of the atom.[1] He observed that the charge is Z times the elementary charge e, where Z is the (already known) position of the element in the periodic table. Rutherford noticed that Z was often approximately half the atomic mass A. (We now know that many nuclei have the same number of neutrons as protons and that the masses of proton and neutron are almost equal, which explains why for many elements Z is to a good approximation equal to A/2.)
This makes it sound like Rutherford "noticed" that the charge on the nucleus is Z, the place of the element in the periodic table, because he noticed that Z was "often approximately half the atomic mass A". The rest of the paragraph explains why that later relationship holds. Unfortunately, it is wrong, because Rutherford had NO chance to make a repeated observations with many elements. In fact, he used only one: gold. This is heavy element in which Z is unfortunately NOT about A/2 (this relationship is true for light elements but not heavy ones), and in fact in gold A/Z is only 0.40. Rutherford found an central charge in gold of about +100 and knowing that gold's A is about 198, suggested the charge at A/2 = +98. But he did NOT suggest the charge was about Z, the atomic number, because he knew very well that gold is at position Z = 79 in the periodic table, and THAT is by definition its atomic number. The suggestion that nuclear charge is exactly Z, was made shortly after by a Dutch amateur scientist, and then proven experimentally by Moseley.
Nice try, Citizendium, but you just didn't get it right. Rutherford's crude measurement of charge gave him about +100 for gold, not the correct +79, or he might have made the connection between nuclear charge and Z (atomic number) you suggest. But it didn't, so he didn't.