The Chemical Bond – What Model Can We Choose to Represent It?

The Chemical Bond – What Model Can We Choose to Represent It?

Chemistry, Physics
Atoms and molecules are small indeed. Until recently, catching even a glimpse an atom was impossible. It still is impossible to see a chemical bond. Despite that, we know quite a few chemical reactions and can predict how many more will turn out. But we could know ever so much more about the scientific world of the very small if we had a very close bond model. We will discuss three bond models that have been used in the past, and to some extent still are used. The rigid model The spring model The force / charge model See the images associated with article. Each depicts one of the models discussed below. The Rigid Model One can depict a diatomic molecule by joining two balls with a thin dowel rod.…
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What Happens at Absolute Zero?

Physics
[caption id="attachment_7397" align="alignright" width="440"] Bose-Einstein condensate at billionths of a degree. Image by NIST[/caption] Classical physics suggests that at absolute zero, particles cease all motion. But what about quantum mechanics, the science of the very small? Ah, therein lies the rest of the story. From Gas to Frigid Solid It is well established fact that heated gas atoms or molecules move with great vigor. In fact, gas expands as energy increases, due to increased particle momentum. The reverse is also true. Cool a gas and it shrinks. Particle motion decreases. Particle momentum decreases. The atoms or molecules come closer together. At some point a liquid forms. Cool the liquid further and the result is a solid. Keep cooling the solid, and in theory it is possible to reach the coldest…
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