January 14, 2012 18:41
Speaking about the shape of bodies, we tend to assume that they have also the size. However, this is not always true: the cue ball is and the shape and size, but the size of the cloud is hard to say, although the form it is usually not in doubt. The most unexpected result of the new model of the atom is an atom that has no geometric dimensions.
We have to accept this result to explain the observed properties of bodies, such as the variety of geometric shapes of crystals. We should not be particularly surprising is — after all, the house is built of brick, but it does not seem strange that the bricks — it's not a house in miniature, as simple as Golitsyn bricks. The bodies around us, there is a color, the smell, there are sizes, but the atoms, which make up these bodies do not possess any of these qualities. They have only one constant feature — the mass. And there is no fixed shape. Only immutable laws of quantum mechanics that govern this form.
But why an atom does not even have the size, why is it so stable? Should not surprise us, too: after all, the earth stands on three pillars, but for millions of years, hanging in the void remains constant orbit. The secret to its stability — in motion. And in the immutability of the dynamical laws that govern the movement.
This is the reason for the stability of atoms, although the laws governing the motion of the electrons are not like the laws of celestial mechanics. Atoms of different elements differ from each mass and charge of the nucleus. But on what basis to distinguish between the two atoms of the same element? For watermelons that question is irrelevant: no one ever saw two absolutely identical watermelons. Distinguish one from another brick Golitsyn is much harder, and only if the broken bricks, the task a little easier.
Since atoms — the smallest bricks in nature — it is exactly the same. If their masses and charges of the nuclei are equal, the atoms can differ only by the shape of the electron cloud — other properties they do not have, the two atoms can be distinguished only in the event that one of them is excited. All unexcited atoms of the same element are indistinguishable among themselves, like bricks of the same form. The role of this form for atoms play the dynamic laws of quantum mechanics, constant and equal for all atoms.
Portraits atom reflect our current level of knowledge about it. This is the modern image of the atom, which replaced the model of Democritus, Thomson, and Bohr. Of course, these "portraits" should not be taken too literally: it is by no means "pictures of atoms", similar images of a vibrating string. Neither simple nor complex instruments, we can not directly measure the electron density distribution within the atom, because it inevitably destroy it (even watermelon to study its properties, pre-cut).
Still, we have much reason to believe this picture: with its help we can consistently explain all the experiences that have led us to this image. Now, we are not surprised that the alpha particles in Rutherford freely fly through the billions of atoms, as in a vacuum. Now, we must be clear and the mechanism of formation of spectral lines: just jump atom changes the shape of the electron cloud distribution, emitting a quantum of energy.
We now have to understand and the frequency shift of spectral lines in electric field (Stark effect) and in a magnetic field (Zeeman effect) charged electron cloud and its various forms under the influence of the fields a little change, and with them the changes and the photon energy, which is necessary expended in order to move from one form to another, and the frequency of the spectral line, which corresponds to the quantum of this.
You can continue on the basis of a new model of the atom to continue the analysis of numerous experiments in atomic physics. But now we need to understand something else: why do we believe that this image of the atom true?