It's a very complex thingyou can understand the basics, but the people who are doing cutting edge reasearch don't even really understand what's going on...so I don't know it to explain it too you.
There are two forces (basically) that govern the formation of clusters from monomers (single atoms or molecules). These are the van der Waals force which repulses the monomers from each other, and surface tension (or surface energy) which bonds them together.
As a cluster grows, these forces change in magnitude. When the cluster contains only a few monomers, the van der Waals force is prevalent and the cluster tends to break up again. As the particle grows, the surface tension begins to take over, and the particle will grow after that. This creates an energy barrier that the particle has to get over. The thermal energy from the air is what allows the particle to get over this barrier. If the air is too cold, there isn't enough thermal energy to make it.
The van der Waals + surface tension is called Gibbs free energy
(There are two forces (basically) that govern the formation of clusters from monomers (single atoms or molecules). These are the van der Waals force which repulses the monomers from each other, and surface tension (or surface energy) which bonds them together.
As a cluster grows, these forces change in magnitude. When the cluster contains only a few monomers, the van der Waals force is prevalent and the cluster tends to break up again. As the particle grows, the surface tension begins to take over, and the particle will grow after that. This creates an energy barrier that the particle has to get over. The thermal energy from the air is what allows the particle to get over this barrier. If the air is too cold, there isn't enough thermal energy to make it.
The van der Waals + surface tension is called Gibbs free energy
kitty meow meow,
Sat 8 Nov 2003, 8:42,
archived)
you can also get theeffect of lattice energy within a crystal cannot be displaced if the temperature is too low. This also has an effect.
I think it's bloody years since I finished my degree
(I think it's bloody years since I finished my degree
DrPoppers Touched by his noodly appendage,
Sat 8 Nov 2003, 8:45,
archived)
Thatwas what they were called, I think. I finished my chemistry degree nearly 10 years ago now and it's all hazy. The only thing I remember clearly is how to make poppers(amyl nitrate)
( DrPoppers Touched by his noodly appendage,
Sat 8 Nov 2003, 8:53,
archived)
hehehehe:) I'm in the middle of my electrical engineering one :)
( kitty meow meow,
Sat 8 Nov 2003, 8:58,
archived)
Wowthat kind of makes sense to me - excellent.
Also, that's the new thing for me to learn today, so I can switch my brain off for the rest of the day now.
(Also, that's the new thing for me to learn today, so I can switch my brain off for the rest of the day now.
Mystery_Bob,
Sat 8 Nov 2003, 8:45,
archived)
heheheit's kind of like van der Waals - electric energy between nuclei and they're electrons if you ever did that. just sort of inverted...
( kitty meow meow,
Sat 8 Nov 2003, 8:47,
archived)
I couldtry to explain quantum mechanical tunnelling. But its a bit shit and odd and generally pointless.
( DrPoppers Touched by his noodly appendage,
Sat 8 Nov 2003, 8:47,
archived)
I can't explain tunnelingI can explain what happens. I don't think I'll ever be able to explain how an electron is just a probablility wave though
( kitty meow meow,
Sat 8 Nov 2003, 8:48,
archived)
it was one of those wierd things that Icould understand clearly when pissed out of my head, but sober was just freaky. Never understood what use it was though
( DrPoppers Touched by his noodly appendage,
Sat 8 Nov 2003, 8:50,
archived)
It has some predicted usebut for the moment it mostly just makes your computer wear out faster.
and it allows you to flow electricity between two chunks of metal that aren't gold or platinum. The thin oxides most metals form would be inpenetrable without it
(and it allows you to flow electricity between two chunks of metal that aren't gold or platinum. The thin oxides most metals form would be inpenetrable without it
kitty meow meow,
Sat 8 Nov 2003, 8:51,
archived)
I have never studied anything like this......but I always understand everything when I am told about it.
As soon as I try to tell someone else about it, I realise I didn't understand anything at all - my brain was just humouring me at the time.
(As soon as I try to tell someone else about it, I realise I didn't understand anything at all - my brain was just humouring me at the time.
Mystery_Bob,
Sat 8 Nov 2003, 8:52,
archived)
I'm thesame with womens shopping. It makes sense what she tells me but when I think about it, its all bollocks
( DrPoppers Touched by his noodly appendage,
Sat 8 Nov 2003, 8:55,
archived)
Ahhhhh!Makes sense!
I always used get mixed up and call Van der Waals forces Van der Valk forces
Thanks for the explanation :)
(I always used get mixed up and call Van der Waals forces Van der Valk forces
Thanks for the explanation :)
Number_6,
Sat 8 Nov 2003, 8:49,
archived)
Do do do do-do-do do-do-do do do dodo-do-do-do do-do do-do doooooooo
( Mystery_Bob,
Sat 8 Nov 2003, 8:51,
archived)
no problem :)It's good to know these things I learn have some use...
( kitty meow meow,
Sat 8 Nov 2003, 8:53,
archived)
It's all good :)My mate's just completed his degree and is about to start tutoring me in A-Level Physics and Mathematics so that one day, my grades will be enough to get into uni :) (I only barely passed when I did them in college)
( Number_6,
Sat 8 Nov 2003, 8:57,
archived)
I get confused by your usage of collegea college is part of a university. Usually a group of departments that have something in common, like here we have the engineering college and the science college.
Or you can have community college, which usually offers the first two years of uni and some two year degrees
(Or you can have community college, which usually offers the first two years of uni and some two year degrees
kitty meow meow,
Sat 8 Nov 2003, 9:01,
archived)
in the uka college is like a sixth form but crap.
Mine was anyone. Boo hiss to Wilmorton Tertiary College, Derby, it is just shit.
Although Oxford, Cambridge and Durham Universities are collegiate Uni's that have seperate colleges. Most other UK universities don't
(Mine was anyone. Boo hiss to Wilmorton Tertiary College, Derby, it is just shit.
Although Oxford, Cambridge and Durham Universities are collegiate Uni's that have seperate colleges. Most other UK universities don't
DrPoppers Touched by his noodly appendage,
Sat 8 Nov 2003, 9:04,
archived)
what's sixth form then?is that where you do your a-levels? I've got the basics of the tests, down I think
( kitty meow meow,
Sat 8 Nov 2003, 9:06,
archived)
As DrPoppers saysour colleges are usually the same as 6th form.
One of the differences here is that 6th form (years 12 & 13 I think) is usually part of the same school, but by then you're 17/18 and having to wear a school uniform at 17/18 is ludicrous and makes it impossible to pull. So lots of us got to college which is basically an external 6th form :)
edit: 6th form or 6th form college is where A-levels are done :)
(One of the differences here is that 6th form (years 12 & 13 I think) is usually part of the same school, but by then you're 17/18 and having to wear a school uniform at 17/18 is ludicrous and makes it impossible to pull. So lots of us got to college which is basically an external 6th form :)
edit: 6th form or 6th form college is where A-levels are done :)
Number_6,
Sat 8 Nov 2003, 9:07,
archived)
ahhh :)all makes sense now.
Our system is simpler, but more crap
(Our system is simpler, but more crap
kitty meow meow,
Sat 8 Nov 2003, 9:08,
archived)