41

Chemistry / Re: Expansion Ratio of Liquid Methane

« on: 09/10/2012 14:10:58 »

It will depend on how warm you get the gas.

I guess I should have been more specific.  What would its expansion ratio be at room temperature?

I will be very specific -- there is no such thing as an expansion ratio at room temperature because liquid methane cannot exist at room temperature -- the critical temperature of methane is –83 °C

Sorry, just another case of me not explaining myself well (I knew that it can't be a gas a room temperature).  I meant:
What is its expansion ratio going from a liquid at its critical temperature of -83° C to a gas at room temperature (20° C)?  (How much will it expand going from a liquid to a gas at said temperatures?) 
Thanks for all the info so far, damocles.  It has been a big help.

42

Cells, Microbes & Viruses / Re: Why do we get brain freeze?

« on: 08/10/2012 20:33:43 »

I don't know the exact science behind it like Don_1 does, but it occurs when something cold comes into contact with the roof of your mouth.  It can be gotten rid of quicker by pressing your tongue against the roof of your mouth.

43

Cells, Microbes & Viruses / Re: What is the purpose of the appendix?

« on: 08/10/2012 20:18:34 »

I have heard before that it may have the purpose of drawing pathogens, etc. away from more important internal organs, but, again, this may be what it is for (there is no hard evdence).

44

Cells, Microbes & Viruses / Re: winter - cold and flu connection

« on: 08/10/2012 18:02:05 »

Your theory is correct. 
More people stay inside during the winter .  That means that there are more pathogens brought inside a smaller space, opposed to outdoors, during the winter.  This, of course, heightens the probability of contracting a pathogen, especially airborne ones. 

45

Chemistry / Re: Is the Periodic Table complete?

« on: 08/10/2012 15:18:33 »

Thanks for the information.
There was only one or two videos.  One was an old black and white video that was supposedly the U.S. army dumping francium into the ocean.  From what I remember, it showed a truck backing up to the edge of a cliff.  A very short time later, a mushroom type cloud came up from the water.  I thought that it could be real with the way that the army tested atomic bombs, etc. in the desert and in the ocean during WWII and the Cold War, but now I guess I know it isn't real.
Thanks again.

46

Chemistry / Re: I was wondering where i could buy carbon electrodes.

« on: 08/10/2012 14:54:19 »

(1) Lab Rat elemental sodium is much more dangerous and much less accessible than caustic soda, which can be readily bought at appropriate stores (hardware stores in this country; do not know what British/North American equivalents are). If the aim is simply to get hold of some caustic soda, there is no need for electrolysis or any other awkward and dangerous chemical procedure, and certainly not to use an extremely dangerous material like metallic sodium. In my student days there was a man at my university who had permanent lifetime employment as a "cleaner" because he had been blinded and had bad facial scars from an accident where water had come in contact with NaK eutectic that was being used as a coolant in some particle physics equipment.

(2) Salt is not a catalyst in this electrolysis reaction, it is a reactant, along with water.


As for #1, I did warn that it was a dangerous reaction that would shoot off glowing debris.  The second one, however, was my mistake.

47

Chemistry / Re: Expansion Ratio of Liquid Methane

« on: 08/10/2012 14:19:29 »

It will depend on how warm you get the gas.

I guess I should have been more specific.  What would its expansion ratio be at room temperature?

48

Chemistry / Re: I was wondering where i could buy carbon electrodes.

« on: 07/10/2012 21:56:17 »

I know what the electrolysis will produce, but I'm doing it outside and wearing a gas mask so I should be alright. Thank you for your concern though.

Do you really need salt in the electrolysis reaction?  If not sodium bicarbonate (baking soda), I don't think, will produce any harmful gases.  However, I am not sure that this will produce sodium hydroxide.  If you have access to it, you can put some elemental sodium in water and this will produce sodium hydroxide.  Be careful, though, as this is quite an explosive reaction-even a small piece of sodium will produce a powerful explosion-small pieces of glowing material may be shot into the air.

49

Chemistry / What is the expansion ratio of liquid methane?

« on: 07/10/2012 20:08:41 »

What is the generally accepted expansion ratio of liquid methane?
I have looked on the internet, but I have found only two places that gave the same value.  Here are the values I've found:
1:650
>851
1:578
1:627
1:627

50

General Science / Re: What makes newer nuclear plants safer?

« on: 07/10/2012 19:40:23 »

One thing they employ in nuclear reactors are control rods controlled with electromagnets.  This is so that, in case of a complete power failure, the control rods will be completely dropped into the reactor core, completely stopping the reaction.

51

Chemistry / Re: Is the Periodic Table complete?

« on: 07/10/2012 18:40:20 »

I have (for once ) a sensible question, when was the Periodic Table first compiled, and have we filled all the gaps yet, or are there more elements to be discovered ?

Theoretically and ideally, the periodic table could be infinitely big.  However, I assume that the farther you go on this infintely big periodic table, the more incredibly unstable the elements would be-maybe even being detectable for far less than milliseconds.  Also, assuming that the next element in Group 1 had the same characteristics as all the other elements except for hydrogen, it would be incredibly explosive in water (look up francium in water videos on youtube).

52

General Science / Re: Why do distant objects appear smaller and less bright?

« on: 05/10/2012 14:15:23 »

Couldn't this be somewhat compared to the Doppler Effect?

53

Chemistry / Re: Need help with a strange mineral

« on: 04/10/2012 21:57:10 »

Have you tried dissolving it in different acids?  Try different size pieces of the material in different acids.  Also, using larger pieces, try doing a scratch test.  Furthermore, you could try to determine its fracture and cleavage.

54

General Science / Re: Does Stuff Become Solid At Absolute Zero ?

« on: 04/10/2012 21:38:10 »

This fact may now be outdated:
Scientists have actually come within a few hundreths of a degree of absolute zero. 
This fact, however, I know is true:
It will be very difficult to achieve absolute zero because whatever chamber you are trying to achieve absolute zero in will have something touching it.  Consequently, this means that heat can be transferred from the object to the chamber.  The only real way to achieve absolute zero in a chamber would be for that chamber to be contained in a complete vacuum.  This is a problem in and of itself.  A complete vacuum calls for a space with absolutely no matter contained in it.  If there is no matter surrounding the chamber, that eliminates the possibility of heat transfer.  So, until a complete vacuum is created, it will more than likely be impossible to achieve the temperature of absolute zero.