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There is little molecule bond between gas molecules, then why we have

by Jackson Lee
Tags: bond, molecule, molecules
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Jackson Lee
#19
Sep3-14, 11:37 AM
P: 35
Quote Quote by sophiecentaur View Post
Exactly the same Equations will describe waves of all types, as long as the system is linear. The interactions between molecules and the departure from an ideal gas will have the effect of introducing non linearity and loss factors into the simple masses-linked-by-springs model. That means that, when the pressure of the gas is relatively low and the gas is far from condensing, any gas will behave ideally. As the pressure increases, the proximity of the molecules will start to affect the simple model. For very high levels of sound, the density in the peaks of pressure (in particular) will no longer relate linearly to the average displacement of the molecules because the energy is not just kinetic but Potential.
By introducing your statement that "Molecules have some inertia" you are falling into the trap of hopping and out between macroscopic and microscopic models. This is very risky, imo. What happens when two molecules approach within their range of influence will depend upon the specific substance but it can be modelled in terms of a proportion of the system energy being transformed to potential. Positive potential mountains of finite width, as opposed to Potential Wells, will surround each molecule's location, causing mutual repulsion.
Frankly speaking, I am unfamiliar with what you said, so I emailed my professor about this topic. If there is any better explanation, I will post it here.
sophiecentaur
#20
Sep3-14, 03:39 PM
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Quote Quote by Jackson Lee View Post
Frankly speaking, I am unfamiliar with what you said, so I emailed my professor about this topic. If there is any better explanation, I will post it here.

And cue Professor. Click. . . .
anhtho
#21
Sep4-14, 11:12 PM
P: 6
At normal conditions, say at atmospheric pressure, gas molecules still collide with each other frequently, so they 'link' together via collision, so that sound can travel.
In vacuum or nearly vacuum condition, the collision number is small, then sound can not travel.


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