HDTenEightyP/NetNews huggingface dataset:
From: CHT012@DJUKFA11.BITNET (H.J. Steinmetz)
Newsgroups: sci.chem
Subject: technetium
Date: 27 Jan 93 12:28:34 GMT
Organization: Forschungszentrum Juelich

Currently I am preparing for my final Ph.d. examination in Tc-chemistry.
Therefore I should know, why only radioactive Tc-isotopes exist. But this
is indeed not a trivial question.

A short and simple explanation would be, that according to Mattauch's rule
no stable Tc-isotopes should exist. Mattauch's rule is a consequence of the
general beta-stability rules. Exceptions are mass numbers 50 and 180.

Mattauch's (empirical) rule says, that no neighbouring stable isobars
(nuclides of the same mass number) exist. So stable isobars have to differ
in two units. If you look at the "chart of nuclides" you can see, that all
Tc-isotopes nearby the "line of beta-stability" have stable isobars. For
example Tc-98 (the longest-lived Tc-isotope) has the stable neighbours Ru-98
and Mo-98. The isotopes Tc-90,91,93,103 and Tc-105 - Tc-110, which have no
stable neighbouring isobars are radioactive because they are to far away from
the "line of beta-stability".

But why are especially Tc and Pm the beta-unstable elements? What makes them
so unique? Until now, I did not find a satisfying explanation in literature.
Who has an idea about this or wants to discuss the question?

Hans-Juergen
Institute for chem.Technology
KFA-Juelich GmbH
Newsgroups: sci.chem
From: crai0010@student.tc.umn.edu ()
Subject: Re: humor
Keywords: humor, jokes, anecdotes, funny
Organization: University of Minnesota
Date: Thu, 21 Jan 1993 16:23:35 GMT

>A chemist is a man who washes his hands _before_ he goes to the bathroom.

The summer before grad school I did an internship with a small
pharmaceutical company.  I found that there was an easy way to tell the
chemists from the biologists:

1) The chemists wash their hands *before* going to the bathroom, and

2) The biologists wear their lab coats to lunch.

-- 
------------------------------------------------------------------------
Elizabeth Craig           |"Did you see the people walk right in from 
Dept. of Chem, Univ. of MN| the street?  That music -- that heavenly 
craig@chemsun.chem.umn.edu| music...Reverend Mother, it called to them."
Newsgroups: sci.chem
From: moroney@world.std.com (Michael Moroney)
Subject: Re: Technetium
Keywords: nucleon shell model proton electron pairing magic numbers
Organization: The World Public Access UNIX, Brookline, MA
Date: Fri, 22 Jan 1993 05:10:01 GMT

blom@husc15.harvard.edu writes:

>In article <C14nyC.Fyp@world.std.com>, moroney@world.std.com (Michael Moroney) writes:

>2,8,20,28,50,82,and 126 turn out to be "magic" numbers.  Nucleii with this
>number of either protons or neutrons are exceptionally stable.  Nucleii with
>a magic number of protons and a magic number of neutrons are even more stable.

>To previous poster: Element 126 is the one, I believe, which is expected to be
>very stable.  (Rather than 114, although that might come pretty close.)  By
>really stable people mean "as stable as Radium" or so, although who knows?  It
>might not be radioactive...  Ha.

I dug up the chemistry book I mentioned (Chemical Principles Dickerson,
Gary, Haight), and it mentions Element 114 and not 126 as the next magic
number.  Specifically element 114 with mass number 298 might be "relatively
stable", as 184 (298-114) is also a magic number.  Now elsewhere they have a
little drawing showing nuclear stability, with number of neutrons on the
X axis, number of protons on the Y axis, and "relative stability" on the
Z axis.  There's a band showing the isotopes, with magic number nuclei being
generally "higher", double magic numbers more so.  The magic numbers are
indicated on the proton and neutron axes, but get this - they aren't
the same past 82.  For neutrons, the numbers shown are 28, 50, 82, 126,
184, 196.  For protons, 28, 50, 82, 114.

So either the magic numbers are not the same or this book is all messed up.
Regardless, it would be interesting to see what happens when elements
#114 and #126 are attempted to be made.

-Mike
From: gtd205a@prism.gatech.EDU (Hody Crouch)
Newsgroups: sci.chem
Subject: Re: Chemical fog
Keywords: Fog
Date: 28 Jan 93 13:26:30 GMT
Distribution: usa
Organization: Georgia Institute of Technology

|to be sure that the kids would not be lying down on the floor where they might
|get an overdose of CO2.
|	Comments, suggestions, flames?
                               ^^^^^^

Not with all that CO2 around.  :-)



-- 
_________________________________________________________________________
Hody Crouch     | Georgia Tech       | Internet: gtd205a@prism.gatech.edu
Chemistry Major | Atlanta, GA 30332  | Snail Mail: 34353 GT Station
________________|____________________|___________________________________
Newsgroups: sci.chem
From: joec@fid.morgan.com (Joe Collins)
Subject: Home Copper plating, was Re: Electroplating info requested
Organization: None
Date: Thu, 28 Jan 1993 19:35:05 GMT

In article <1993Jan27.180500.7512@gw.wmich.edu> x90hornbach1@gw.wmich.edu writes:
>I'm interested on doing some at home electroplating.  I know that you can mail
>order kits and pay $30 for the chemicals and some wire, but I would rather put
>something together myself.

I have done copper plating many times with my son. I hope to do silver
plating (when I can get my hands on AgNO3) someday.

COPPER PLATING:
Get Copper Sulphate (pentahydrate version sold as root killer in hardware
  store - they have nerve charging what they do since its mostly water).
Mix some up with warm/hot water in a beaker or pyrex glass.
Let it dissolve but put plenty of CuSO4 in so you can't
 dissolve it all. Careful - its toxic.
Connect what you wish to electroplate to the negative side of a DC
 power source, at least 3 volts but don't overdo it (or it comes out TOO
 fast).
Connect something copper to the positive side of the same DC power source.
Put both in the copper sulfate solution and watch.
After a few short minutes, you will see the copper plating start to happen.

---
If I had silver nitrate, I would do something very similar to the above.

TIP- low voltage is better, gives a better (robust) coating. Try using
     20V DC instead and you will see the difference.

have fun.

Joe
joec@morgan.com
From: parks@binah.cc.brandeis.edu
Newsgroups: sci.chem
Subject: Computer apps. in organic chem.
Date: 26 Jan 93 19:06:28 GMT
Reply-To: parks@binah.cc.brandeis.edu
Organization: Brandeis University

Interested in computer applications in organic chemistry?  We are 
looking for a few good people to join the group here and I would be
pleased to give you further information.  Our focus is on the logic
of synthesis design and its computer realization.  If you are
interested, please call me at (617) 736-2520 or drop me a line
through snail- or e-mail.  If you send me your snail-mail address
I can send you some reprints.

    --	Prof. J.B.Hendrickson
    snail: Dept. of Chemistry, Brandeis University, Waltham MA 02254-9110
   bitnet: hendrickson@brandeis
 internet: hendrickson@binah.cc.brandeis.edu

    REFERENCES:  J.B.Hendrickson, et al. -  
	review: Accts. Chem. Res. 19, 274 (1986); 
	fragmentations/rearrangements: J. Am. Chem. Soc. 108, 6748 (1986); 
	basic computing: J. Chem. Inf. & Comp. Sci. 29, 137 (1989); 
	multiple constructions: ibid. 29, 145 (1989); 
	reaction indexing: ibid. 30, 403 (1990); 
	reaction retrieval: J. Am. Chem. Soc. 113, 902 (1991); 
	overview: Angew. Chem. Intl. Ed. 29, 1286 (1991).
Newsgroups: sci.chem
From: aflorjan@magnus.acs.ohio-state.edu (Alan S Florjancic)
Subject: Re: Dining Escapades.
Organization: The Ohio State University
Date: Sun, 24 Jan 1993 14:31:57 GMT


Jay...

The fizzle you see in soda when salt is added is merely the evolution of the 
CO2 in the pop(carbonation) when salt is dissolved in the solution.  Salt is
much more soluable than the carbon dioxide and the pop can only dissolve so 
much
material, so the less soluable thing comes out of solution...

The other reaction is an acid-base reaction with the baking soda(base) and
acetic acid....

Alan S. Florjancic
Newsgroups: sci.chem
From: S.R.Carlo@daresbury.ac.uk  (S.R. Carlo)
Subject: Re: Looking for site with current contents +
Keywords: current contents
Organization: SERC Daresbury Lab., Warrington, U.K.
Date: Tue, 26 Jan 1993 10:59:52 GMT

In article <1k195hINN2in@crcnis1.unl.edu> pickrell@hoss.unl.edu (Andrew Pickrell) writes:
>I am interested in finding access to a site with current contents adn
>science citation indexes on-line.  If these are available to outside users,
>please leave me e-mail with instructions.
>
>Other relavent information would be appriciated. (I am currently only
>aware of CARL for database searches).
>
>Thanks,
>Andrew Pickrell
>
>--
>==============================================================================
>Andrew Pickrell                  | All opinions expressed are copyrighted
>UNL Dept. of Chemical Engineering| material. If you are illegally using them,
>EMail :pickrell@hoss.unl.edu     | prepare to be sued. ;)

In Engalnd at The University of Bath there is an on-line SCI updated every 2
weeks and searchable backwards to about 1982 by author, journal, language etc
You need a PW and ID to use it - I believe there is a site license
You can also have the results of your search mailed to you

Mail : BIDSHELP@UK.AC.BATH

They should be able to help you out

Steve Carlo
SXC@uk.ac.dl.cxa
From: denis@pangea.Stanford.EDU (Denis Schiozer)
Newsgroups: sci.chem
Subject: HELP
Date: 24 Jan 1993 01:31:05 GMT
Organization: Stanford Univ. Earth Sciences
NNTP-Posting-Host: pangea.stanford.edu


Does anybody can help me with these questions?

1) 10 largest chemical companies (annual sales) in the world?
   (not including oil companies)

2) 10 chemicals produced in largest volume in US?
   (not including fuel)

3) Five essential metals whose ores are not found in US?

4) What is the most important ore containing silicon and
   how sillicon is manufactured from it?

Thank you very much for your help!

My e-mail is : denis@pangea.stanford.edu


Newsgroups: sci.chem
From: clumsden@TrentU.CA (Cam Lumsden)
Subject: Re: ATTN: howard/all
Reply-To: clumsden@TrentU.CA
Organization: Trent University, Peterborough
Date: Mon, 25 Jan 1993 13:39:55 GMT

In article <1993Jan24.222547.7441@gw.wmich.edu>, 159muehlberg@gw.wmich.edu writes:
>
>Also, I have heard of and seen a demo in which, when constantly stirred,
>changes colors....help?
>
This demo known as the BLUE BOTTLE experiment is outlined by J. Arthur 
Campbell in "Why Do Chemical Reactions Occur" (Prentice-Hall 1965)

Stock Solutions

1.  Aqueous soduim(or potassium) hydroxide (40g/L)
2.  Aqueous dextrose (glucose) (24g/L)
3.  Methylene Blue indicator (1% in ethanol)
4.  Indigo Carmine indicator (1% in water)

Reaction 1.  (In a 1L flask)

250 mL NaOH solution
250 mL dextrose solution
1 mL methylene blue

On swirling the solution turns from clear to blue.  On relaxing, back to 
clear.

Reaction 2.  (In a 1L flask)

250 mL NaOH solution
250 mL dextrose solution
1 mL Indigo Carmine indicator

On gentle agitation the solution turns from green to red.  On more vigorous 
agitation turns to yellow.
N.B.  This one takes a few minutes to get working, so don't shake with 
impatience.

Both of these reactions are decompositions so mix the two solutions 
together right before your demo.

Safety Note : the sodium hydroxide solution is caustic so have the flasks 
well stoppered.


If anyone else knows of nifty little experiments or quirks of nature please 
post or mail.

						Cam Lumsden
						clumsden@trentu.ca
Newsgroups: sci.chem
From: bill@texan.rosemount.com (William Hawkins)
Subject: Re: After-shave question
Organization: Rosemount, Inc., Minneapolis, MN
Date: Thu, 21 Jan 1993 18:21:20 GMT

In article <1993Jan20.081901.3909@leland.Stanford.EDU> jchokey@leland.Stanford.EDU (James Alexander Chokey) writes:
>
>	Here's the problem.  This weekend I opened a (mostly full) bottle
>of after-shave that was a couple years old (about 3 or 4 years, I'd guess).
>Let me be more specific. I had bought it about 3 or 4 years ago, opened it
>shortly after purchase, and basically not opened it again until this weekend.
>When I bought  and first used it, the aftershave was fine.  When I opened it 
>and used it this week-end, it smelled quite vile, and I had to throw it out.
>
>	What happened to my aftershave to make it turn bad? 

What have you done in the last few years to improve your sense
of smell?  Almost all perfumed personal products smell quite
vile in this era of synthesized fragrances.

Bill Hawkins
From: tt@wag.caltech.edu (Toshi Takeuchi)
Newsgroups: sci.chem
Subject: Re: CAS-online
Date: 23 Jan 1993 22:09:20 GMT
Organization: California Institute of Technology, Pasadena, CA
NNTP-Posting-Host: sgi1.wag.caltech.edu

>> Ok, we got into CAS from internet, but how do you capture your search? We 
>> would like more information about the commands once you are connected through
>> telnet.
>> Thanks in advance!

Unfortunately I only saw followups to this, and I didn't feel like editing
my .newsrc, so forgive me for answering on the net.  Anyhow, if you're
getting onto internet from a unix platform, there is usually a command
called script which will take ALL output from the screen and dump it
into a file called typescript.

You would type script, then do whatever you normally do--telnet,CAS-search,
then exit from the script shell, then you should be able to read the
file typescript which has all of the info from your session.
From: blom@husc15.harvard.edu
Newsgroups: sci.chem
Subject: Re: free alkali metals
Date: 25 Jan 93 00:54:40 GMT
Article-I.D.: husc15.1993Jan24.195440.19756
Organization: Harvard University Science Center

In article <1993Jan25.001014.19062@reed.edu>, nuke@reed.edu (Bill Newcomb) writes:
> aankrom@nyx.cs.du.edu (Anthony Ankrom) writes:
>>
>> Is there a practical laboratory procedure for obtaining free alkali
>>metals such as lithium and sodium from their salts? One example might be
>>electrolysis, but is the aparatus necessary for this easilly set up in a
>>lab?
> 
> Not really. You need stuff like sintered iron or graphite crucibles. Not to
> mention the current supply, with appropriate overcurrent and thermal limiting. 
> And a means to keep NaCl molten :-)
> 
> I haven't ever had to actually buy sodium, as it seems to be omnipresent in
> most reasearch labs. I would wager that it's pretty cheap.
> 
> Bill Newcomb
> --
> ~/.oo


Cheap, yes, but not free...  :)
Newsgroups: sci.chem
From: summers@max.arc.nasa.gov (David Summers)
Subject: Re: soap bubbles
Organization: /usr/lib/news/organization
Date: Wed, 27 Jan 1993 20:14:08 GMT

robert@arbo.microbiol.uwa.edu.au ask about recipies for soap bubbles:
I don't have any recipies per say... I would recommend any good
dishwashing detergent (hand).  Since people associtate bubbles with
cleaning, companies have spent a lot of money on hand dishwashing
deteregents that make a lot of long lasting bubbles.  Degergents
for maching clothes and dishwashers are not as good.  People can't
see the bubbles and they can get in the way so they are not 
"optimized" for them.

Dave Summers
DPSummers@Ames.ARC.NASA.Gob

--
David Summers
DPSummers@Ames.ARC.NASA.Gov
415-604-3225
415-326-6274
Newsgroups: sci.chem
From: peby@vancouver.UVic.CA (Paul  Eby)
Subject: Re: Chemical Word Processor for PC
Reply-To: peby@vancouver.UVic.CA
Organization: University of Victoria, Victoria, BC, Canada
Date: Tue, 26 Jan 93 18:23:42 GMT


In article 28938@cc.gatech.edu, gn@cc.gatech.edu (toM o. genesE) writes:
>Hello,
>
>  I am looking for an *inexpensive* (student budget ;-) chemical word
>processing system for a PC.  I'd like to be able to connect ring
>structures, add groups, etc., as well as supplement the drawings with
>text if necessary.
>
>  Any suggestions?  Please respond via email.
>>  Thanx.
>

ChemText is fairly good, although I have no idea how much it costs...



Newsgroups: sci.chem
From: summers@max.arc.nasa.gov (David Summers)
Subject: Re: soap bubbles
Organization: /usr/lib/news/organization
Distribution: usa
Date: Thu, 28 Jan 1993 01:39:58 GMT

>***************relevant stuff deleted****************
>>Dave Summers
>>DPSummers@Ames.ARC.NASA.Gob
>                    ^^^^ ^^^
>We know... we know... . Gob, gob, gob...
>We all know what you (and your employer, 
>and your employer's employer) do with our 
>tax money... :)
>

Oops!

Dave Summers
DPSummers@Ames.arc.nasa.GOV


--
David Summers
DPSummers@Ames.ARC.NASA.Gov
415-604-3225
415-326-6274
From: x90hornbach1@gw.wmich.edu
Newsgroups: sci.chem
Subject: Electroplating info requested
Date: 27 Jan 93 18:05:00 EST
Organization: Western Michigan University

I'm interested on doing some at home electroplating.  I know that you can mail
order kits and pay $30 for the chemicals and some wire, but I would rather put
something together myself.

I'm familiar with the general electroplating theory, but that is about it.  If
anyone has done anything like this, I would appreciate some info.  Here is what
I want to do:

Plate things with silver, gold, chromium, or nickel.

Small steel objects.  Once I get good, I want to plate a shotgun barrel.  That
is as big as it'll get.  (no bumpers)

specific questions:

What is the procedure?

What chemicals do I need?

Where can I get cheap supplies? (mail order chemical house?)

How good of results can a layman like myself achieve?

What kind of power supply should I use? (batteries, transformer, etc)

Wkind of surfaces work best with certain chemicals (Bl? (Blued shotgun barrel,
for instance.)

Any other helpful info?

Please Email and I'll summarize later.

thanks
John Hornbach

Newsgroups: sci.chem
From: jgd@dixie.com (John De Armond)
Subject: Re: Brehmstrehhlung X-rays - Safety
Date: Tue, 26 Jan 93 16:10:42 GMT
Organization: Dixie Communications Public Access.  The Mouth of the South.

lachlan@dmp.csiro.au (Lachlan Cranswick) writes:

>If your company has a "safety first" attitude, then I think you
>should be trying your best to setup the equipment that nothing
>above background is measured by the counts detector. (i.e., nothing
>above 2 counts per second)  

This is overly severe.  The concept of ALARA (as low as reasonably 
achievable) should be practiced.  ALARA does NOT demand complete
elimination of radiation from the workplace.

>As our company has a safety first policy, anything above background
>counts coming from our Powder X-ray diffractometers is considered
>a leak even if they have negligable biological damage value.
>While it can be argued that there is no health risk, it is definitely
>a good feeling when your superiors imply they care about your heath
>enough to spend money on your safety rather than their company cars, etc.
>We have had over $16,000 authorized for a full radiation enclosure
>because of a small leak (3 times background counts -
>CuK X-rays) that was only detectable
>1cm from the source.  This gives two complete levels of safety on our
>diffractometers which some people would argue is total overkill.

This is unfortunate because it makes a mockery of radiation safety.  It
opates those who abstractly fear radiation but for those with some knowledge
of radiological procedures, it is the radiation equivalent of crying
wolf.  Pretty soon the mockery destroys confidence in the system.  People
begin to assume that ALL radiological hygene procedures are "wolf crying"
and ignore them.

John

John
-- 
John De Armond, WD4OQC               |Interested in high performance mobility?  
Performance Engineering Magazine(TM) | Interested in high tech and computers? 
Marietta, Ga                         | Send ur snail-mail address to 
jgd@dixie.com                        | perform@dixie.com for a free sample mag
Need Usenet public Access in Atlanta?  Write Me for info on Dixie.com.
Newsgroups: sci.chem
From: mroussel@alchemy.chem.utoronto.ca (Marc Roussel)
Subject: Re: Published values of bond energies
Organization: Department of Chemistry, University of Toronto
Distribution: sci.chem
Date: Thu, 28 Jan 1993 01:49:25 GMT

In article <1993Jan27.190213.27488@cs.sfu.ca> jones@cs.sfu.ca (John Jones)
writes:
>I've been checking the values given for the energies of some common
>chemical bonds in various textbooks, and have been surprised to find wide
>variations in the values given.  For example, take the C-C, C=C and
>C[triple bond]C energies; I found the following values (in kJ/mol)
>
[Table showing a 10-20% variances in textbook-reported bond energies deleted.]
>
>What is the cause of these discrepancies?

     Bond energies vary a lot from molecule to molecule.  The figures
shown in typical textbook tables are averages over several different
kinds of molecules containing a certain "type" of bond.  I put the word
"type" in quotation marks in the previous sentence because, for
instance, the C-C bond in an aldehyde is quite a different thing than
that in a normal hydrocarbon.  As you can imagine, the average value you
arrive at will depend crucially on your sample.

>Suppose I actually needed to know the bond energies for some practical
>purpose, how would I come up with a reliable figure?

     If you really needed an estimate of a bond energy, your best
strategy would be to try to find a more detailed table and to use a bond
energy from a closely related molecule.  For a small example of what I
mean, look at the table on p. 1064 of Kemp and Vellaccio's Organic
Chemistry.  There are better bond energy tables around, but I don't
happen to have such a thing in my personal library.
     Usually, it's best to try to avoid using bond energies.  They are
sometimes useful for ballpark arguments, but usually standard
thermodynamics tables can be made to yield the same information and
because the latter tables are almost always more comprehensive, it's
easier to gauge the variability of reaction energies from them.

				Marc R. Roussel
                                mroussel@alchemy.chem.utoronto.ca
Newsgroups: sci.chem,sci.misc,sci.bio
From: nuke@reed.edu (Bill Newcomb)
Subject: Re: Glues from milk?
Organization: Reed College, Portland, OR
Date: Fri, 22 Jan 1993 20:18:48 GMT
Distribution: usa

cheeze@wam.umd.edu (Joshbo ) writes:
>Everyone,
>
>I was reading about glues made from milk curd -- casein glue I
>think it's called.

Elmer's glue is casein glue, as another poster pointed out. Let me point out
that buying Elmer's (or store brand) glue is cheaper than making it from
milk, not to mention easier. 

>
>Also, When this glue dries, I assume it becomes rigid anD inflexible.
>What can you add to the glue to make it dry flexible -- like a 
>plastic?  Or, how could I synthesize a flexible plastic of my
>own if the glue doesn't work?

But the glue does work!-) What is it you want to do with it? You might try
friendly plastic (available at art supply stores), which is a plastic that
becomes soft at a low enough temperature to handle, but which is quite
solid, and somewhat flexible, at room temp. If you need more flexible, or
adhesive (fp is not adhesive) try RTV silicone cement or rubber cement. 

Hope this helps. I've made casein glue before, and it makes a mess. If you
want to really use it for anything you should do the precipitation twice to
make it a bit cleaner. I never added baking soda, so mine took a long time
to dry :-)

Bill Newcomb

--
~/.oo
From: 159muehlberg@gw.wmich.edu
Newsgroups: sci.chem
Subject: ATTN: howard/all
Date: 24 Jan 93 22:25:47 EST
Organization: Western Michigan University

A few posts back, howard@netoom.com posted a opinion of my humorous tale...


What is this alt.***.***( I don't remember the rest)

I would have mailed you, howard, but my sys gave me the mailerdaemon 
at your address.

Ellen Muehlberger
Western Michigan University
159muehlberg@gw.wmich.edu
"The union of beauty and order is found in a laboratory."

Also, I have heard of and seen a demo in which, when constantly stirred,
changes colors....help?