pulkit

It was a part of my first year course on metric spaces (atleast we were supposed to know the result of the theorem-not its derivation)

Now in the second year its cropped up again in my discrete mathematics course..

On second thought, I can understand why you may not have heard of it, the course I did in my first year is actually a post graduate course that was only a couple of years ago included in our under graduate curriculum (and then being in comp sci meant that we had to chose the more difficult of the two maths courses on offer namely the one mentioned above)

Is there no simple and inexpensive way to extract iodine from KI because I believe that in the US and UK, salt is iodized with KI. Over here, they use KIO3

Given a particular temperature, how exactly do you plan to maintain it ? I don't think its all thateasy a task to stick to a range of less than 15 degrees or so

[MATH]Na_2SiO_3 + 6 HF \rightarrow Na_2SiF_6 + 3 H_2O [/MATH]

Not exactly [MATH]SiF_4[/MATH]

If H2O2 is acting as an oxidising agent, it'd produce H20 and not O2

just remember to first pour the water, then the acid

Lots of sulphuric acid + little water = BOOM !

Lots of water + Little sulphuric acid = Dilution

But does that still hold for nitric acid ?

I have not worked with it myself because red cabbage is frightfully expensive around here. But this resource would have me believe that it does indeed change colour at an apropriate pH to be useful as an indicator in the reaction in question.

If methyl orange is hard to get, you could always use a home-made indicator.

Red-cabbage juice does the trick.

hmm' date=' you could do a nitrogen trichloride synth, then oxidize it, a bit of magnesium shards (NOT POWDERED) and a little iodine with a solution of conc perchloric acid, barium nitrate, calcium and cobalt carbonate, sodium fluoaluminate, lithium carbonate, and strontium carbonate and nitrate.

 

the above would cause a powerful immediate explosion, with a very hot multicolored flame lasting a good long time afterwards.[/quote']

 

Oh my dear God !!

 

Have yu actually EVER done this ??

Where on Earth did you get all that stuff from ?

It seems like this something like "atomic units" that was taught to us while we did quantum mechanics. We definde these units by taking value of fundamental constants like h bar, electronic charge, 4 pi epsilon not etc. all to be equal to unity. Once we did this, suddenly the Schrodinger equation took a very beautiful and simple form. We also came up with some nice units to define length on the atomic scale.

When you work in such a system the chances of manual error reduce greatly and calculations are massively simplified.

Soda lime silicate glass is amongst the cheapest and common types. That is what is generally described in text books, it would have a formula of [MATH]Na_2SiO_3[/MATH]

I think a major factor going against your idea is the cost factor. Even if the materials needed are cheaper than the conventional metals used, the manufacturig process itself would need to change. This would not be financially viable in most if not all cases.

Another factor is marketability. It won't be very easy to convince people to buy this product. A large section of the automobile industry caters to family and commercial vehicle, and for them such vehicles won't make much sense. Even attacking the single passenger market would be rather difficult. Many people would feel a lot safer (I am talking about the mental attitude here) in a metallic shell rather than a flimsy rubbery one.

Lastly, I am not so convinced that a more flexible material would be safer in a collision situation. The force should be distributed over the body of the vehicle and not be transfered to the individual inside. Why would a material like the one mentioned, help in doing this ?

What exactly is hbar?

Planck's constatnt divided by 2 pi. Its a very convenient quantity as it occurs everywhere in quantum mechanics.

i cant believe that thas a theorem name. its just this

 

a less than b ' date=' and b less than a implies a=b. i have seen this before for like showing that a set A=B. but can't believe a trivial thing like this should have a name[/quote']

 

I find it strange that you are doing a major in maths and you haven't heard of this theorem. Its one of the first things you do when you start axiomatic set theory.

When you say elliptical cylider, yet you know that its a 4-dimensional figure, exactly which property/properties of the ellipse or cylider do you generalise to the fourth dimension. It seems easy to carry forward spheres into n dimensions, but how do you carry forward cylinders and ellipses ?

Old batteries often contain an amino complexed zinc ion, it often oozes out as a dark fluid from them. Using too old a battery would introduce this into the rection too. But I think its Manganaese dioxide which is reacting over here - it is a dark solid.

Dammit people, radiation is nothing to be worried about... or maybe it is. Just don't keep too strong gamma-stuff near you, and DON'T, I mean DON'T keep alpha-radiators near aluminum or beryllium. They kick off neutrons, and neutron radiation is something not to be played with. Beta and alpha radiators aren't too dangerous by temselves, just don't eat or inhale them.

Do you acctually have radioactive stuff in your collection ?

The best way to write experiments is to break down your report into various sub-headings like : Aim, Procedure, Observations etc.

And then you MUST report everything you observe and also try and put down everything in points and do not write long paragraphs - nobody likes to read those.

In school, I remember being told that some of the lanthanides are used to increse workability of metals at high temperatures and are thus used in such alloys. This invoked two questions :-

a) How expensive are these lanthanides to get hold of and how much is it possible to obtain ?

b) I was also taught of their general extraction procedures, but never told if there were any commercial mines / quarries where the actual ore / minerals may be found. Where would one go looking for these minerals, i mean geographical area ?

Note : As far as Thorium is concerned it is available from a particular type of sand that is available in considerable quantities on beaches in a southern state in India. I don´t know of any areas where Uranium is found naturally.

Thorium and Uranium are not lanthanides, they are actinides. Most of those are radioactive and I wouldn´t want to handle them

I was curious about stuff like Promethium, Praseodymium, Lanthanum, Neodymium, Europium, Gadolinium, Terbium, Holium etc. etc.

Cerium ions are commonly used oxidiising agents aren´t they ?

How about the Rare Earth elements - i mean the lanthanides - is there any way of getting hold of those ?

We still get mercury thermometers here. Whenever someone wants mercury, they go ahead and buy a couple of thermometers.

Magnesium is extremely easy to get, we had lots in our school lab.

Where do you get Gallium and Indium ?

Does anyone have a pure sample of Arsenic ?

I am in IIT (Indian Institute of Technology)

Hey I don't plan to stay in India.

I am realistic I know that in most probability I'll work somewhere abroad. Doing a degree in maths, would not leave many options to you but become a university professor or researcher, wheres the money then ?

Walter Feit and John Thompson