# Tag Info

1

There is plenty of theoretical and experimental evidence that CO2 is linear and H2O has a tetrahedral geometry. For instance, these geometries have been calculated ab initio (from quantum mechanics) several times in Car-Parrinello studies: they indeed converge to a linear O=C=O configuration, or an approximately tetrahedral structure for H2O, for the ground ...

1

In H2O the center atom has four valence electrons, in CO2 the center atom has six valence electrons. H2O forms two simple bonds, while CO2 forms two double bonds. Why should it behave the same? Simple qualitative answer: Think about the ball and stick model (Not sure, how these are really called. I mean the ones with plastic spheres and soft plastic bonds). ...

2

Disclaimer: I will try my best to make this rather long story short. First of all, we must say that we are talking about the so-called equilibrium geometry - molecular geometry that corresponds to the true minimum on the potential energy surface, a surface which describes the energy of a molecule as a function of nuclear coordinates. Secondly, potential ...

0

Ion Transport is by Connvection and Diffusion. Only very small Part by Migration. As Long as there is no anodic and cathodic reaction I would say the concentration is Not changing in any Part of the Solution.

2

For good doping you need two things: (1) get enough dopant in to be useful in changing carrier concentrations, and (2) having an energy level close to a band edge to generate electrons (holes) in the band, rather than making a mid-level recombination center. The below is assuming you are trying to dope Silicon. Data is generally from Sze's excellent ...

4

The article you refer to is about the electrolytic splitting of water. A 100% efficient electrolytic cell would require a voltage of about 1.23V to split water, but for various reasons a simple electrolytic cell requires about 1.48V. The difference between the voltages is called the overpotential, and it increases the amount of power needed to split the ...

1

If you look at the 2 graphs, the force varies directly as the slope of the potential energy curve ($F\propto$ slope of $PE$)(or is it the other way around?). There is a reference to attraction in the PE graph because the atoms will stay together if the distance keeps the PE negative. If the distance were to decrease so that the PE is positive, the atoms ...

3

What does negative potential energy mean here? Not much. The particular value of potential energy isn't important at all in classical physics. But changes in potential energy are. You could shift everything up so that $U>0$ everywhere, and you'd still get the same physics. (Why, you ask? Well, would the force change?) So why would people choose to ...

0

In general, the absolute energy of a physical system does not matter for these potential problems. However, for convenience sake, one often choses to make the potential energy term at infinite separation equal to zero. If you were to hold the two atoms infinitely far away from each other, they will first experience an attractive force, because the ...

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