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.split() Qeustion

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  .split() Qeustion eschneider92@comcast.net - 2013-08-13 21:51 -0700
    Re: .split() Qeustion Gary Herron <gary.herron@islandtraining.com> - 2013-08-13 22:12 -0700
      Re: .split() Qeustion Alister <alister.ware@ntlworld.com> - 2013-08-14 08:30 +0000
        Re: .split() Qeustion Joshua Landau <joshua@landau.ws> - 2013-08-14 11:31 +0100
          Re: .split() Qeustion Alister <alister.ware@ntlworld.com> - 2013-08-14 13:29 +0000
          Re: .split() Qeustion Duncan Booth <duncan.booth@invalid.invalid> - 2013-08-15 09:15 +0000
            Re: .split() Qeustion wxjmfauth@gmail.com - 2013-08-15 02:46 -0700
              Re: .split() Qeustion Chris Angelico <rosuav@gmail.com> - 2013-08-15 10:54 +0100
              Re: .split() Qeustion Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-15 11:22 +0000
                Re: .split() Qeustion wxjmfauth@gmail.com - 2013-08-15 06:58 -0700
        Re: .split() Qeustion Peter Otten <__peter__@web.de> - 2013-08-14 13:45 +0200
        Re: .split() Qeustion Joshua Landau <joshua@landau.ws> - 2013-08-14 12:55 +0100
          Re: .split() Qeustion wxjmfauth@gmail.com - 2013-08-14 07:32 -0700
            Re: .split() Qeustion random832@fastmail.us - 2013-08-14 13:05 -0400
              Re: .split() Qeustion Steven D'Aprano <steve@pearwood.info> - 2013-08-15 07:17 +0000
            Re: .split() Qeustion Chris Angelico <rosuav@gmail.com> - 2013-08-14 18:14 +0100
              Re: .split() Qeustion wxjmfauth@gmail.com - 2013-08-15 00:46 -0700
                Re: .split() Qeustion Lele Gaifax <lele@metapensiero.it> - 2013-08-15 16:38 +0200
                Re: .split() Qeustion MRAB <python@mrabarnett.plus.com> - 2013-08-15 15:54 +0100
                Re: .split() Qeustion Lele Gaifax <lele@metapensiero.it> - 2013-08-15 17:30 +0200
                Re: .split() Qeustion Chris Angelico <rosuav@gmail.com> - 2013-08-15 16:43 +0100
                  Re: .split() Qeustion Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-16 04:13 +0000
                    Re: .split() Qeustion Roy Smith <roy@panix.com> - 2013-08-16 00:29 -0400
                      Re: .split() Qeustion Dave Angel <davea@davea.name> - 2013-08-16 05:27 +0000
                        Re: .split() Qeustion Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-17 02:38 +0000
                          Re: .split() Qeustion Chris Angelico <rosuav@gmail.com> - 2013-08-17 03:45 +0100
                      Re: .split() Qeustion Gene Heskett <gheskett@wdtv.com> - 2013-08-16 10:30 -0400
                      Re: .split() Qeustion Gene Heskett <gheskett@wdtv.com> - 2013-08-16 10:24 -0400
                        Re: .split() Qeustion Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2013-08-17 11:16 +1200
                    Re: .split() Qeustion Ben Finney <ben+python@benfinney.id.au> - 2013-08-16 15:59 +1000
                      Re: .split() Qeustion Roy Smith <roy@panix.com> - 2013-08-16 07:14 -0400
                        Re: .split() Qeustion wxjmfauth@gmail.com - 2013-08-16 06:14 -0700
                          Re: .split() Qeustion Roy Smith <roy@panix.com> - 2013-08-16 09:23 -0400
                            Re: .split() Qeustion wxjmfauth@gmail.com - 2013-08-17 01:09 -0700
                              Re: .split() Qeustion Roy Smith <roy@panix.com> - 2013-08-17 07:55 -0400
                              Re: .split() Qeustion Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2013-08-18 11:30 +1200
                                Re: .split() Qeustion wxjmfauth@gmail.com - 2013-08-18 00:17 -0700
                        Re: .split() Qeustion Grant Edwards <invalid@invalid.invalid> - 2013-08-16 13:59 +0000
                Re: .split() Qeustion Joshua Landau <joshua@landau.ws> - 2013-08-15 17:54 +0100
                Re: .split() Qeustion Chris Angelico <rosuav@gmail.com> - 2013-08-15 19:28 +0100
                  Re: .split() Qeustion Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-16 04:17 +0000
                Re: .split() Qeustion Joshua Landau <joshua@landau.ws> - 2013-08-15 19:40 +0100
                Re: .split() Qeustion Terry Reedy <tjreedy@udel.edu> - 2013-08-15 17:40 -0400
                  Re: .split() Qeustion Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-16 04:22 +0000
                Re: .split() Qeustion Dave Angel <davea@davea.name> - 2013-08-15 22:56 +0000
                  Re: .split() Qeustion Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-16 04:39 +0000
                    Re: .split() Qeustion Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-16 04:41 +0000
            Re: .split() Qeustion Tim Chase <python.list@tim.thechases.com> - 2013-08-14 12:29 -0500
            Re: .split() Qeustion Skip Montanaro <skip@pobox.com> - 2013-08-14 12:38 -0500
            Re: .split() Qeustion Chris Angelico <rosuav@gmail.com> - 2013-08-14 18:46 +0100
            Re: .split() Qeustion Terry Reedy <tjreedy@udel.edu> - 2013-08-14 15:45 -0400
    Re: .split() Qeustion Dave Angel <davea@davea.name> - 2013-08-14 05:35 +0000
    Re: .split() Qeustion eschneider92@comcast.net - 2013-08-13 22:44 -0700
    Re: .split() Qeustion Krishnan Shankar <i.am.songoku@gmail.com> - 2013-08-13 22:37 -0700
    .split() Qeustion "Alfonso Andalon Jr." <alfonsoandalon@gmail.com> - 2013-08-16 21:31 -0700

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#52554

On Thu, Aug 15, 2013 at 4:30 PM, Lele Gaifax <lele@metapensiero.it> wrote:
> MRAB <python@mrabarnett.plus.com> writes:
>
>> On 15/08/2013 15:38, Lele Gaifax wrote:
>>> wxjmfauth@gmail.com writes:
>>>> PS A "mole" is not a number.
>>>
>>> Oh, nice to know. And OOC, what is a "mole" in your stupid science?
>>> OTOH, WTF does that matter in current thread and with Python in general?
>>>
>> A "mole" is a term from chemistry:
>>
>> http://en.wikipedia.org/wiki/Mole_%28unit%29
>
> Yes, I know that, but AFAIU, there is a closer correlation between "a
> mole" and "a number" than between "a string" and "the number of bytes an
> arbitrary computer [language] needs to store it". It did not come out as
> funny as I meant :)

A mole is as much a number (6e23) as the light year is a number (9.5e15).

ChrisA

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#52572

On Thu, 15 Aug 2013 16:43:41 +0100, Chris Angelico wrote:

> A mole is as much a number (6e23) as the light year is a number
> (9.5e15).

Not quite. A mole (abbreviation: mol) is a name for a specific number, 
like couple (2) or dozen (12) or gross (144), only much bigger: 6.02e23. 
And I can't believe I still remember that value :-) It's normally used 
only for atoms, ions or molecules, but in principle you could talk about 
anything. E.g. the population of the world is a mere 1.2e-14 mol.

A light-year, on the other hand, is a dimensional quantity. Whereas mole 
is dimensionless, light-year has dimensions of Length, and therefore the 
value depends on the units you measure in:

1 light-year:

= 3.724697e+17 inches
= 0.30660139 parsec
= 9.4607305e+12 kilometres

etc.


-- 
Steven

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#52575

In article <520da6d1$0$30000$c3e8da3$5496439d@news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote:

> On Thu, 15 Aug 2013 16:43:41 +0100, Chris Angelico wrote:
> 
> > A mole is as much a number (6e23) as the light year is a number
> > (9.5e15).
> 
> Not quite. A mole (abbreviation: mol) is a name for a specific number, 
> like couple (2) or dozen (12) or gross (144), only much bigger: 6.02e23. 
> And I can't believe I still remember that value :-)

I remember it as 6.022e23 :-)

In my high school chemistry class, there was a wooden cube, about 1/2 
meter on a side, sitting on the lecture desk in the front of the room.  
The only writing on it was "6.022 x 10^23".  It sat there all year.

The volume of the cube was that of 1 mole of an ideal gas at STP.

> A light-year, on the other hand, is a dimensional quantity. Whereas mole 
> is dimensionless, light-year has dimensions of Length, and therefore the 
> value depends on the units you measure in:
> 
> 1 light-year:
> 
> = 3.724697e+17 inches
> = 0.30660139 parsec
> = 9.4607305e+12 kilometres

Hold your hands out in front of you, palms facing towards each other, 
one shoulder-width apart.  That distance is about one light-nanosecond.

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#52578

Roy Smith wrote:

> In article <520da6d1$0$30000$c3e8da3$5496439d@news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote:
>
>> On Thu, 15 Aug 2013 16:43:41 +0100, Chris Angelico wrote:
>> 
>> > A mole is as much a number (6e23) as the light year is a number
>> > (9.5e15).
>> 
>> Not quite. A mole (abbreviation: mol) is a name for a specific number, 
>> like couple (2) or dozen (12) or gross (144), only much bigger: 6.02e23. 
>> And I can't believe I still remember that value :-)
>
> I remember it as 6.022e23 :-)
>
> In my high school chemistry class, there was a wooden cube, about 1/2 
> meter on a side, sitting on the lecture desk in the front of the room.  
> The only writing on it was "6.022 x 10^23".  It sat there all year.
>
> The volume of the cube was that of 1 mole of an ideal gas at STP.
>
>> A light-year, on the other hand, is a dimensional quantity. Whereas mole 
>> is dimensionless, light-year has dimensions of Length, and therefore the 
>> value depends on the units you measure in:
>> 
>> 1 light-year:
>> 
>> = 3.724697e+17 inches
>> = 0.30660139 parsec
>> = 9.4607305e+12 kilometres
>
> Hold your hands out in front of you, palms facing towards each other, 
> one shoulder-width apart.  That distance is about one light-nanosecond.

Narrow shoulders.

I figure it just under a foot.  I once attended a lecture by Grace
Hopper where she handed out "nanoseconds," pieces of wire about a foot
long.  She said that the beaurocrats were always asking how much is a
nanosecond, and couldn't imagine what a billionth was like.  So she gave
them something physical.

-- 
Signature file not found

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#52615

On Fri, 16 Aug 2013 05:27:49 +0000, Dave Angel wrote:

> I figure it just under a foot.  I once attended a lecture by Grace
> Hopper where she handed out "nanoseconds," pieces of wire about a foot
> long.  

Is that based on the speed of light in a vacuum, speed of light in 
copper, speed of electron drift in copper, speed of sound in copper? Or 
perhaps it was aluminium wire? :-)

> She said that the beaurocrats were always asking how much is a
> nanosecond, and couldn't imagine what a billionth was like.  So she gave
> them something physical.

Hmmm, given when Grace Hopper was active in the navy, I would have 
thought that the simplest way to imagine a billionth would be "one dollar 
is a billionth of the US National Debt" or "one person is a billionth of 
the world's population". None of which really helps the typical person 
visualise a billionth, since the typical person can't really visualise a 
billion people or a billion dollars.

I think a simple analogy that works is: the width of a single human hair 
is a billionth of 100 metres (or yards, for Americans). People can 
visualise 100 metres, and they can visualise a hair. No need to relate 
things to the speed of light, which most people cannot visualise, or the 
circumference of the earth, or the distance from New York to Tokyo, or 
from Venus to Mars at aphelion :-)



-- 
Steven

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#52616

On Sat, Aug 17, 2013 at 3:38 AM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> On Fri, 16 Aug 2013 05:27:49 +0000, Dave Angel wrote:
>
>> I figure it just under a foot.  I once attended a lecture by Grace
>> Hopper where she handed out "nanoseconds," pieces of wire about a foot
>> long.
>
> Is that based on the speed of light in a vacuum, speed of light in
> copper, speed of electron drift in copper, speed of sound in copper? Or
> perhaps it was aluminium wire? :-)
>
>> She said that the beaurocrats were always asking how much is a
>> nanosecond, and couldn't imagine what a billionth was like.  So she gave
>> them something physical.
>
> I think a simple analogy that works is: the width of a single human hair
> is a billionth of 100 metres (or yards, for Americans). People can
> visualise 100 metres, and they can visualise a hair.

Further information here:

http://en.wikipedia.org/wiki/Grace_Hopper#Anecdotes

It was specifically looking at satellite comms, and it's the speed of
light through a vacuum (the ideal maximum speed of satellite
communication signals). Check the Wiki page's footnotes for reliable
references.

ChrisA

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#52596

On Friday 16 August 2013 10:27:36 Dave Angel did opine:

> Roy Smith wrote:
> > In article <520da6d1$0$30000$c3e8da3$5496439d@news.astraweb.com>,
> > 
> >  Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote:
> >> On Thu, 15 Aug 2013 16:43:41 +0100, Chris Angelico wrote:
> >> > A mole is as much a number (6e23) as the light year is a number
> >> > (9.5e15).
> >> 
> >> Not quite. A mole (abbreviation: mol) is a name for a specific
> >> number, like couple (2) or dozen (12) or gross (144), only much
> >> bigger: 6.02e23. And I can't believe I still remember that value :-)
> > 
> > I remember it as 6.022e23 :-)
> > 
> > In my high school chemistry class, there was a wooden cube, about 1/2
> > meter on a side, sitting on the lecture desk in the front of the room.
> > The only writing on it was "6.022 x 10^23".  It sat there all year.
> > 
> > The volume of the cube was that of 1 mole of an ideal gas at STP.
> > 
> >> A light-year, on the other hand, is a dimensional quantity. Whereas
> >> mole is dimensionless, light-year has dimensions of Length, and
> >> therefore the value depends on the units you measure in:
> >> 
> >> 1 light-year:
> >> 
> >> = 3.724697e+17 inches
> >> = 0.30660139 parsec
> >> = 9.4607305e+12 kilometres
> > 
> > Hold your hands out in front of you, palms facing towards each other,
> > one shoulder-width apart.  That distance is about one
> > light-nanosecond.
> 
> Narrow shoulders.
> 
> I figure it just under a foot.  I once attended a lecture by Grace
> Hopper where she handed out "nanoseconds," pieces of wire about a foot
> long.  She said that the beaurocrats were always asking how much is a
> nanosecond, and couldn't imagine what a billionth was like.  So she gave
> them something physical.

Chuckle.  I always figured Grace Hopper had to have been a stand up comic 
in some previous life.  She sure could translate the problem into something  
the paper pushers could grok.

Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene> is up!
My views 
<http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml>
Nachman's Rule:
	When it comes to foreign food, the less authentic the better.
		-- Gerald Nachman
A pen in the hand of this president is far more
dangerous than 200 million guns in the hands of
         law-abiding citizens.

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#52597

On Friday 16 August 2013 10:07:12 Roy Smith did opine:

> In article <520da6d1$0$30000$c3e8da3$5496439d@news.astraweb.com>,
> 
>  Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote:
> > On Thu, 15 Aug 2013 16:43:41 +0100, Chris Angelico wrote:
> > > A mole is as much a number (6e23) as the light year is a number
> > > (9.5e15).
> > 
> > Not quite. A mole (abbreviation: mol) is a name for a specific number,
> > like couple (2) or dozen (12) or gross (144), only much bigger:
> > 6.02e23. And I can't believe I still remember that value :-)
> 
> I remember it as 6.022e23 :-)
> 
> In my high school chemistry class, there was a wooden cube, about 1/2
> meter on a side, sitting on the lecture desk in the front of the room.
> The only writing on it was "6.022 x 10^23".  It sat there all year.
> 
> The volume of the cube was that of 1 mole of an ideal gas at STP.
> 
> > A light-year, on the other hand, is a dimensional quantity. Whereas
> > mole is dimensionless, light-year has dimensions of Length, and
> > therefore the value depends on the units you measure in:
> > 
> > 1 light-year:
> > 
> > = 3.724697e+17 inches
> > = 0.30660139 parsec
> > = 9.4607305e+12 kilometres
> 
> Hold your hands out in front of you, palms facing towards each other,
> one shoulder-width apart.  That distance is about one light-nanosecond.

Or a quite noticeable color shift when you are cutting coax cables for 
color phase matching, which we often had to do in an analog NTSC broadcast 
facility.  Where a 1 degree shift, may or may not have been noticeable, was 
the cable equivalent of 7.7601420788892939683e-10 seconds, which was for 
the small foam cored cables used for such, with a Propagation Velocity of 
0.78*C, only a very short length of cable.  I'd have figured how much but I 
got lost pushing buttons in kcalc just now and came up with something I'd 
have to use a micrometer to measure. Its been close to 30 years since I had 
to do such calcs on a near daily basis.  Your trivia factoid for the day, 
and I now return you to the regularly scheduled discussion going no where 
specifically.  :-)

Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene> is up!
My views 
<http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml>
I suppose that in a few hours I will sober up. That's such a sad
thought. I think I'll have a few more drinks to prepare myself.
A pen in the hand of this president is far more
dangerous than 200 million guns in the hands of
         law-abiding citizens.

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#52611

Gene Heskett wrote:
> Where a 1 degree shift, may or may not have been noticeable, was 
> the cable equivalent of 7.7601420788892939683e-10 seconds, which was for 
> the small foam cored cables used for such, with a Propagation Velocity of 
> 0.78*C, only a very short length of cable.  I'd have figured how much but I 
> got lost pushing buttons in kcalc

Python says about 180mm.

-- 
Greg

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#52579

Steven D'Aprano <steve+comp.lang.python@pearwood.info> writes:

> Not quite. A mole (abbreviation: mol) is a name for a specific number, 
> like couple (2) or dozen (12) or gross (144), only much bigger: 6.02e23. 
> And I can't believe I still remember that value :-)

Avogadro's Number is worth remembering, for mocking the pseudo-science
of homeopathy <URL:http://www.1023.org.uk/what-is-homeopathy.php>.

By knowing the scale of Avogadro's Limit – the maximum dilution of
matter before one can confidently say the solution contains none of the
original substance – one can look at the claims of homeopathy and
confidently say that it can't contain anything effective.

working-to-laugh-alt-med-out-of-the-world-ly yrs,

-- 
 \       “I'm having amnesia and déjà vu at the same time. I feel like |
  `\              I've forgotten this before sometime.” —Steven Wright |
_o__)                                                                  |
Ben Finney

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#52585

In article <mailman.613.1376632775.1251.python-list@python.org>,
 Ben Finney <ben+python@benfinney.id.au> wrote:

> Avogadro's Number is worth remembering, for mocking the pseudo-science
> of homeopathy <URL:http://www.1023.org.uk/what-is-homeopathy.php>.

You have obviously never argued science with a homeopath if you believe 
that knowing Avogadro's number will in any way shake their faith.

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#52587

-----

A mole is an amount of matter measured in [kg] .
The Avogadro's number can only be a dimensionless number, [1] .
The Avogadro's constant is the Avogadro's number (of "pieces" or
"objects") per mol, [1 / mol].

A chemist has to work and is always working in mole; as his
balance can only measure a mass, the calculation mole <-> mass
is always mandatory.

Why did I put this "mole" in the post scriptum?

Because there is a tendency on this list to be extremely
confused and to compare what is not comparable (eg. comparaison
of mole and Python large number, number and radian, byte and
unicode transformation unit).

jmf

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#52588

In article <2d88bc0f-fdcb-4685-87ed-c17998dd3137@googlegroups.com>,
 wxjmfauth@gmail.com wrote:

> A chemist has to work and is always working in mole; as his
> balance can only measure a mass, the calculation mole <-> mass
> is always mandatory.

That's because chemists are lazy.

The recipe says, "Add one mole of carbon atoms".  So, does the chemist 
follow the recipe and count out 6.022 x 10^23 atoms like he's supposed 
to?  No.  He says, "I don't have time for that.  I'll just weigh out 12 
grams.  Good enough for government work."  Sheesh.

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#52619

Le vendredi 16 août 2013 15:23:37 UTC+2, Roy Smith a écrit :
> In article <2d88bc0f-fdcb-4685-87ed-c17998dd3137@googlegroups.com>,
> 
>  wxjmfauth@gmail.com wrote:
> 
> 
> 
> > A chemist has to work and is always working in mole; as his
> 
> > balance can only measure a mass, the calculation mole <-> mass
> 
> > is always mandatory.
> 
> 
> 
> That's because chemists are lazy.
> 
> 
> 
> The recipe says, "Add one mole of carbon atoms".  So, does the chemist 
> 
> follow the recipe and count out 6.022 x 10^23 atoms like he's supposed 
> 
> to?  No.  He says, "I don't have time for that.  I'll just weigh out 12 
> 
> grams.  Good enough for government work."  Sheesh.

--------

You don't understand the concept of "mole".

In this formal reaction

Na  + Cl   -->   NaCl

the chemist combines *one mole* of sodium and *one
mole* of chlorine to get *one mole* of sodium chloride
(cooking salt).

It's independent of the number of "particles" in a mole.

It's not a question of laziness, the chemist can only weight
22.98 g of sodium to work with one mole of sodium, because the
nature is like this.


The work with relative quantities has a name: stoichiometry.


jmf

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#52620

I wrote:
>> The recipe says, "Add one mole of carbon atoms".  So, does the 
>> chemist follow the recipe and count out 6.022 x 10^23 atoms like 
>> he's supposed to?  No.  He says, "I don't have time for that.  I'll 
>> just weigh out 12 grams.  Good enough for government work."  Sheesh.

In article <8584caa1-1593-41ac-8e0c-4ac4639913d6@googlegroups.com>,
 wxjmfauth@gmail.com wrote:
 
> You don't understand the concept of "mole".

You don't understand the concept of "joke" :-)

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#52645

wxjmfauth@gmail.com wrote:
> Na  + Cl   -->   NaCl
> 
> the chemist combines *one mole* of sodium and *one
> mole* of chlorine to get *one mole* of sodium chloride
> 
> It's independent of the number of "particles" in a mole.

The actual number chosen for the unit is arbitrary, but
number of particles is still the central issue. The
important thing is to have the *same* number of particles
of Na and Cl.

Weight only comes into it because it's totally impractical
to count particles. And the particular number 6.02e23 is
chosen because it happens to give a convenient relationship
between number of particles and grams. If chemists had
decided to use ounces instead, the number would be different.

-- 
Greg

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#52651

Le dimanche 18 août 2013 01:30:14 UTC+2, Gregory Ewing a écrit :
> wxjmfauth@gmail.com wrote:
> 
> > Na  + Cl   -->   NaCl
> 
> > 
> 
> > the chemist combines *one mole* of sodium and *one
> 
> > mole* of chlorine to get *one mole* of sodium chloride
> 
> > 
> 
> > It's independent of the number of "particles" in a mole.
> 
> 
> 
> The actual number chosen for the unit is arbitrary, but
> 
> number of particles is still the central issue. The
> 
> important thing is to have the *same* number of particles
> 
> of Na and Cl.
> 
> 
> 
> Weight only comes into it because it's totally impractical
> 
> to count particles. And the particular number 6.02e23 is
> 
> chosen because it happens to give a convenient relationship
> 
> between number of particles and grams. If chemists had
> 
> decided to use ounces instead, the number would be different.
> 
> 
> 
> -- 
> 
> Greg

--------


"The actual number chosen for the unit is arbitrary, but
number of particles is still the central issue."

No.


"The important thing is to have the *same* number of particles
of Na and Cl."

Yes.
And it is precisely for that reason, a chemist works in "mole
arithetic".

Same reaction as above

Na  + Cl   -->   NaCl

in pseudo math, with n = number of elements in a mole.


n * Na  + n * Cl  --> n * NaCl    <==>
n * (Na + Cl)  -->  n * NaCl      <==> division by n
Na + Cl   -->  NaCl


for any n.

----

The determination of n, the number of elements in
a mole, is an indipendent and separate problem.
(BTW, a very complicate task).


jmf

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#52589

On 2013-08-16, Roy Smith <roy@panix.com> wrote:
> In article <mailman.613.1376632775.1251.python-list@python.org>,
>  Ben Finney <ben+python@benfinney.id.au> wrote:
>
>> Avogadro's Number is worth remembering, for mocking the pseudo-science
>> of homeopathy <URL:http://www.1023.org.uk/what-is-homeopathy.php>.
>
> You have obviously never argued science with a homeopath if you believe 
> that knowing Avogadro's number will in any way shake their faith.

He wasn't talking about arguing with a homeopath -- he was talking
about mocking homeopathy.

If you accept the premise of homeopathy having to do with the
transferring of the essence or memory or whatever it's called, the
fact that the final "solution" contains none of the original solute is
irrelevant, and they will freely admit that none of the solute is
actually present.  It's all a complete and utter scam, of course.

-- 
Grant Edwards               grant.b.edwards        Yow! I'm a nuclear
                                  at               submarine under the
                              gmail.com            polar ice cap and I need
                                                   a Kleenex!

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#52561

On 15 August 2013 16:43, Chris Angelico <rosuav@gmail.com> wrote:
> A mole is as much a number (6e23) as the light year is a number (9.5e15).

A mole is a number. A light year is a unit.

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#52565

On Thu, Aug 15, 2013 at 5:54 PM, Joshua Landau <joshua@landau.ws> wrote:
> On 15 August 2013 16:43, Chris Angelico <rosuav@gmail.com> wrote:
>> A mole is as much a number (6e23) as the light year is a number (9.5e15).
>
> A mole is a number. A light year is a unit.

A mole is an amount of something. Avogadro's Number is a number, which
is what I was hinting at :)

ChrisA

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