John Cuthber

Like some unfortunate, ill-washed schoolboys, it is named after its unpleasant smell. Unlike the schoolboys, this isn't just a nickname.

invisible and yellow are mutually exclusive.

 

also, post a source for that.

No they are not, and can you please cite your source.

Incidentally, I'm sure that something can be invisible and yellow; I saw it on this website somewhere.

Individual pollen grains are invisible and yellow.

Here's a picture of one

You can't see it, but everyone knows pollen is yellow.

Sometimes I worry that "big brother" might read these threads; sometimes I hope he does.

"To be fair, if you're going to do things like wear funny pants, hunt foxes and say, "Tally ho!", then you should be prepared to have that image used against you. "

You rather seem to have missed the fact that we don't.

In fact, it's illegal (well the fox hunting bit's banned, if we banned "funny pants" the American tourists would be turned back at the borders.)

BTW you really need to learn that pants is not a synonym of trousers, and a large fraction of the UK population are puzzled that the US has not only concluded it needs a government-run Fanny, but is prepared to talk about it in public ;-)

Anyway, to get back to the topic- who's teeth are set on edge every time someone refers to a "quantum jump"?

Another myth is that glutamate is some "artificial additive" It might be added to some things but, for example, some cheeses are over 1% glutamate. If you think cheese is artificial , tomato juice is about 0.3% glutamate.

My other pet hate is the idea that food additives are bad- in many cases, like MSG, they are natural components of other foods. Not just that, but if the improve the keeping properties of the food they may well be reducif exposure to things like aflatoxin.

I think we may have frightened the poor OP away which is a pity.

Well, you can use a concave mirror to focus the beam of a transmitter too.

Depends what you mean by elliptical.

The curve on a concave mirror is often part of a sphere because they are easy to make but parabolic and ellipsoidal mirrors are also made.

The mirror that focusses the light from a flash tube onto the ruby rod in a "classic" ruby laser is elliptical. It would work perfectly well for radio waves or microwaves.

Why would there be one?

(and I'm an analytical chemist BTW)

There are lots of different fungi called penicillium. Very few produce penicilin.

http://en.wikipedia.org/wiki/Penicillium

Long ago when I was at school I noticed that there were transformers in the boxes with the speakers in. I later learned that these meant that the signal could be distributed at a higher voltage (typically about 100V) and lower current. Since the current is quite low the power loss due to the resistance of the cables isn't a problem. Searching for "100 volt line transformer" will get lots of examples.

There's an article about the idea in wiki.

http://en.wikipedia.org/wiki/AVLIS

Perhaps the most telling quote is

"In the largest technology transfer in U.S. government history, in 1994 the AVLIS process was transferred to the United States Enrichment Corporation for commercialization. However, on June 9, 1999 after a $100 million investment, USEC cancelled its AVLIS program."

People don't generally cancel things that look like they might work in practice.

Anyway the answer to the question is more or less

"the 238U absorption peak shifts from 502.74 nanometers to 502.73 nm in 235U." because you can then use a second laser (that is only absorbed by the excited species) to do the ionisation.

That's a perfectly big difference if you are looking at a laboratory process, but it's a rather small one if you are looking at commercial production.

I think I read it somewhere on the net as an example of how the "land of the free" is a bit of an irony.

You can buy a gun but not a three necked flask.

Liquid nitrogen is stored in Dewar vesels with loose fitting lids for several days or even weeks in the lab where I work. We don't keep it under pressure. Large storage Dewars are pressurised, but this is for ease of dispensing rather than to stop it boiling.

http://www.cryospeed.co.uk/cryospeed/equipment/dewars_and_accessories/25_litre_dewars_and_accessories/index.asp

Anyway, as has been pointed out, dry ice simply isn't cold enough to freeze all the components in crude oil. Also the mixture will have a lower freezing point than the components so I think the best you would get would be a very viscous goo.

With liquid nitrogen you could freeze it, but it would melt as it warmed up so a block of it wouldn't lst long.

What on earth do you want it for anyway?

They are sometimes known as "hot wire" meters.

http://www.practicalphysics.org/go/Experiment_698.html;jsessionid=alZLdQlAHb1

Sometimes I'm amazed by what you can find on the net.

http://www.elephantdungpaper.com/

Bones are largely calcium phosphate, but they are toughened by the presence of proteins. I doubt that those proteins are exaclty the same in fish as they are in lamb or beef. Careful extraction of the protein followed by analysis would, I'm sure tell fish from meat, and I think it might tell you a bit about the species of fish too.

If it fizzes in boiling water it's still sodium bicarbonate and I'm pretty sure that it would be stable for years under normal storage conditions.

I will look at the expiration date on the stuff in the lab if we have any.

I know that the NRC indicates that small quantities of certain radioactive material are legal to possess, but I'm not sure what the exact amounts are. I'm pretty certain that ANY amount of a fissile material is illegal to own, but I haven't been able to find any specifics.

 

I'm pretty sure that the processing of any ore, or any other chemical purification of nuclear material is illegal. (E.G. if you have your Uranyl Nitrate and try to make pure Uranium out of it, you'd be breaking the law).

The Americium in smoke detectors is a fissile material and I'm pretty sure it's legal to own one.

I wonder if the lawyers have written some law that forbids making an atom bomb.

Perhaps I'm just naturally suspicious.

Is this a question about "If I put a magnet next to the meter that the electricity company installed will it go round more slowly and give rise to a smaller utility bill?"

It's not nice to play with in any country but which ones have that law?

The good old US of A - the land of the free. (I think I'm allowed to do it here in the UK but I'm not sure).

IIRC the OP is based in a state where owning lab glassware is restricted anyway, so the local laws on radioactive materials are likely to be strict.

I'm not a lawyer but I think that the answer to the OP's question is yes, but not legally. The Am in those detectors is only exempted from the license system because it is part of an "exempted product" . If you take it out of the smoke detector you are breaking the law.

Also, it's not nice stuff to play with.

What soluble form could a base bath convert the iron into?

It's quite possible that the heat of the Fe +S reaction will have partly melted the glass in which case cleaning it won't help.

On the other hand, if it's just got FeS stuck to it, then you need something that will dissolve FeS.

What is the classic way of making H2S in a lab?

Is this just for interest or is there some reason you can't just use wax?

OK so you took the trouble to make Na from NaOH and you are thinking about making Cl2 from HCl.

Then you ask what other way there might be of making salt?

Did you really not think about just dissolving the NaOH in water and neutralising it with the HCl?

I know this site is full of people doing things the hard way, but they usually know that that is what they are doing.