Science Questions

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Hydrogen is not a metal. In essence, it's just a collateral that is only good for the electrostatic charge it brings with it. It is one proton, and one electron (maybe a neutron too), so it can't really be classified with the other Alkaline Metals (or much of anything for that matter).

Edit: That case is much different. At a certain pressure, even hydrogen crystalizes into a solid (regardless of the temperature). Granted, this pressure would have to be very high and would entail a lot of heat energy, but it would work. I suppose it is possible that Jupiter's core could be solid Hydrogen, but there would be nothing capable of surviving under that pressure (unless we made a suit of diamond), so landing is out of the question. Just think, a little more pressure and the nuclear fusion process on Jupiter could start, and we'd have two stars to worry about.
 
You obviously weren't in AP Chem. Did you ever learn about Critical Pressure and Critical Temperature?
 
Under extreme pressures it gets colder doesn't it? I heard that the core was somewhere around 2K or 3000K or something like that. And of course the grade 10 science teacher wouldn't tell you that, Grade 10 science I ridiculously pointless and inane. Everything we've done so far, I already know.
 
Jpec07
You obviously weren't in AP Chem. Did you ever learn about Critical Pressure and Critical Temperature?
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Correct... I didn't take AP Chem. I took AP Government and Economics. :)
And no, I don't remember learning anything about critical pressure and critical temperature...
 
Jpec07
You obviously weren't in AP Chem. Did you ever learn about Critical Pressure and Critical Temperature?
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That's what I thought, but I guess they're not 100% critical. There are exceptions, as always, apparently.
 
Yes, I revived this thread...but it was hot for a little while. Anyway, I would like to know what the difference is between a compound/molecule being "aqueous" and "liquid".
 
In answer to PS: it's quite simple. A liquid is a substance past it's melting point - a liquid has slightly dispersed molecules, but molecules that still keep close enough to maintain a consistent volume (though not shape). An aqueous substance is when a solid is placed into a liquid and dissolves - for example when salt (NaCl) is placed in water.

Continuing the pressure talks:

The required temperature for a state change is dependent on pressure - a good example has to do with backpacking. Most backpackers will know that cooking food takes longer at higher elevations. Due the pressure decrease, the required temperature for water to boil goes down; this in turn decreases the speed of the cook.

The best way to look at how pressure affects the state of matter is by looking at something called a phase diagram:

http://www.chm.bris.ac.uk/motm/uf6/phasediag.gif

Notice how as the pressure increases, the temperature required for a phase change increases as well. Each substance has its own phase diagram, though this is a good general example.
 
Thanks, they never made that clear as to what the difference was in school. I even asked her and she completely dodged the question. Stupid ignorant science teachers not teaching properly.
 
*edit* Just realised my mistake. Ignore.
 
Ok, here's an aviaton question. What are the names of the effects in the pictures here?

f14-photo-vf101-18l.jpg


f14-photo-vf101-21l.jpg


I assume both are some sort of condensation, but I'd like to know if there are specific terms for both, and what causes these phenomena to occur.
 
I think I know this one. You're right, that is condensation, althought I don't think they have specific names; the only ones I've heard are contrails (short for "condensation trails" ...unexpected, huh? :dunce: ) or vapor trails; but the latter ones are the ones you can see at high altitudes, coming -apparently- from the exhaust of the engines. The contrails usually happen because the low pressure zones of the wing (and the propeller too, sometimes) can cool the air around them in a way to induce condensation, but they usually happen when the wing is 'creating' more pressure than normal: i.e. under high loads, or better said, when pulling more than 1 G; about 2 or 3 G's, if the conditions are right (temperature and saturation of the air). They can also occur (although the trail is 'lighter') when the aircraft extends flaps when landing.
 
Does absolute humidity and temperature have anything to do with it? :confused:
 
PS
Does absolute humidity and temperature have anything to do with it? :confused:
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Yep, mostly the humidity part. The air has to be almost fully saturated for contrails to appear. And, I'm not so sure about this (more specifically, the "why" part), but it seems that the cooler the air is, the more likely it is for contrails -and exhaust trails- to appear. That's why you can only see the vapor trails at higher altitudes, where the temperature is lower.
 
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