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The Birth of Chemistry
Posted: 29 August 2007 11:24 AM   [ Ignore ]   [ # 31 ]
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CoryDuchesne - 29 August 2007 10:36 AM
ghost - 27 August 2007 12:49 AM


as far as isolating the first chemicals… think about all the things that are pure in everyday life: we can find quartz crystals, gold pieces, iron ore, carbon/soot… WATER! and an “experiment” does not have to be terribly elaborate to discover a substance’s properties. the unfortunate soul who lights a fire too close to a methane-bubbling swamp, for example?

But still, that example doesn’t shed any light on why the period table of elements was organized the way that it was. 

the periodic table is a different animal than a broad library of pure chemicals.

the periodic table is a chart of the most simple substances known to man: elements. however, chemicals or compounds (or whatever you want to call them), aren’t always pure elements but they can be pure substances. for example, we can have ultra pure water, but water is made up of hydrogen and oxygen.

your question regarding the organization of the periodic table is best described by reading texts and other science history books. google is your friend, though, if you’re looking for an overview. here’s one link that seems to help summarize some of the work done:

http://www.sparknotes.com/chemistry/fundamentals/periodictable/section1.html

evaporating sea water generally leaves a residue—of salt, which can be analyzed further.

Well, since salt isn’t an element on the periodic table of elements, the question begs to be asked, how exactly can you analyze salt further?  How did they determine that salt (NaCl) was comprised of two elements: Sodium and Chloride? 

table salt is actually sodium and chloriNe but that’s okay. wink i guess i have two answers/suggestions for answering this question (and similar questions about “how do we KNOW?”)...

1) i can field questions like this till i’m blue in the face… provide you with links and texts to read, but there’s no one answer for “how did they determine compound X was composed of elements Y and Z, et al?” a lot of science was trial and error. i do stress learning more about the history of the scientific method. and if you’re curious about specific compounds or elements, look those up as your interests are piqued. the way the first person who decided sodium chloride was, in fact, sodium chloride was not the same way that someone discovered that water was, in fact, hydrogen and oxygen. not to mention the fact that when someone asks me “how do they do that?” i’m prone to starting at the birth of the question being asked, and there are always a lot of wrong turns along the way before they say “A-HA!” and make a concrete conclusion based on lots of testing.

2) i know this is a cop-out answer, but i really think if you’re interested enough to pursue this academically, that a greater grasp would be obtained the more you learn in the classroom. as one progresses in the study of chemistry, they learn more about how to analyze everything, and about “how stuff works.” if someone hands you an unknown white powder and says “what is this?” there’s a lot of factors to take into account, and a lot of those come from a decent education, and an appreciation of this is what makes it easier to understand how sciensts decades ago were able to isolate, document, and understand salts in general, or other compounds and elements.

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Posted: 29 August 2007 12:18 PM   [ Ignore ]   [ # 32 ]
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Narwhol,

narwhol - 27 August 2007 08:27 AM

Most of the elements of the periodic table were known when Dimitri did his thing they were presently grouped in a modified version of Newlands’ octaves

Yeah, but how did they come to be known?

[elements] were further arranged according to their mass numbers.

How were mass numbers of elements determined? 

What dmitri did was organize [elements] according to their properties

How did he know their properties?

When these elements were discovered, this was seen as confirmation for his periodic table. 

What was the first few of these elements to be discovered, and how were they discovered?

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Posted: 29 August 2007 01:10 PM   [ Ignore ]   [ # 33 ]
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ghost - 29 August 2007 11:24 AM
CoryDuchesne - 29 August 2007 10:36 AM
ghost - 27 August 2007 12:49 AM


as far as isolating the first chemicals… think about all the things that are pure in everyday life: we can find quartz crystals, gold pieces, iron ore, carbon/soot… WATER! and an “experiment” does not have to be terribly elaborate to discover a substance’s properties. the unfortunate soul who lights a fire too close to a methane-bubbling swamp, for example?

But still, that example doesn’t shed any light on why the period table of elements was organized the way that it was. 

the periodic table is a different animal than a broad library of pure chemicals.

[nods]

the periodic table is a chart of the most simple substances known to man: elements. however, chemicals or compounds (or whatever you want to call them), aren’t always pure elements but they can be pure substances. for example, we can have ultra pure water, but water is made up of hydrogen and oxygen.

Right, and what I want to know is, what were the observations which justified the belief in oxygen, hydrogen, etc?

your question regarding the organization of the periodic table is best described by reading texts and other science history books.

I’ve been searching a great deal, and because I’m not finding what I’m looking for, I’m asking you, Narwhol and others questions.

http://www.sparknotes.com/chemistry/fundamentals/periodictable/section1.html

Yeah, that site doesn’t have what I’m looking for.  Science popularizers and enthusiasts too readily impart theories, failing to illustrate the initial observations and experiments that justified the theories to begin with.  This is the major weakness of the scientific community, as there is a certain religiousness to how eagerly it’s members gobble up mere theory with questioning it’s basis.

evaporating sea water generally leaves a residue—of salt, which can be analyzed further.

Well, since salt isn’t an element on the periodic table of elements, the question begs to be asked, how exactly can you analyze salt further?  How did they determine that salt (NaCl) was comprised of two elements: Sodium and Chloride? 

table salt is actually sodium and chloriNe but that’s okay. wink i guess i have two answers/suggestions for answering this question (and similar questions about “how do we KNOW?”)...

1) i can field questions like this till i’m blue in the face… provide you with links and texts to read, but there’s no one answer for “how did they determine compound X was composed of elements Y and Z, et al?” a lot of science was trial and error.

Huh?  Just because a lot of ‘trial and error’ science preceded the discovery of the atom’s nucleus, doesn’t mean that there was not a very specific, and very interesting experiment that was responsible for the nucleus’s detection. (I found it very fascinating to learn about Rutherford’s gold foil experiment)  Likewise, I am quite certain that there are very interesting experiments on record somewhere responsible for detecting specific elements on the periodic table for the first time.  I want to know what these experiments were, and I will find out! 

i do stress learning more about the history of the scientific method.

Why are you assuming I don’t have an understanding of the scientific method?

and if you’re curious about specific compounds or elements, look those up as your interests are piqued.

I’ve done that, and I’ve not found what I’m looking for.

the way the first person who decided sodium chloride was, in fact, sodium chloride was not the same way that someone discovered that water was, in fact, hydrogen and oxygen.

I never expected the method used to discover one element to be the same method required for discovering a different element. 

not to mention the fact that when someone asks me “how do they do that?” i’m prone to starting at the birth of the question being asked

I’m not sure what you mean.  Are you suggesting that maybe my question is based on wrong assumptions?  That my question is irrational?

Well, you did say that you were a chemist.  If you have something to teach me, please do so. 

2) i know this is a cop-out answer, but i really think if you’re interested enough to pursue this academically, that a greater grasp would be obtained the more you learn in the classroom.

Ghost, this is how I see it.

It’s either a) You are someone who has answers to my questions, or b) You are someone who doesn’t and are instead inclined to direct me to someone else who you think has the answers that you are lacking. 

I may very well take a course in the fundamentals of chemistry, but until then, I have very specific interests and I would very much appreciate any insightful answers you may have to my questions.  If you don’t think you have the answers to my questions, just say so. 

as one progresses in the study of chemistry, they learn more about how to analyze everything, and about “how stuff works.”

But Ghost, I’m primarily a philosopher.  I’m interested in knowing how we know ‘how stuff works’.  wink

if someone hands you an unknown white powder and says “what is this?” there’s a lot of factors to take into account, and a lot of those come from a decent education

I have no doubt that there is value in being able to do this, but please understand, that is not what I’m presently interested in doing.  Maybe eventually, but not now. 

and an appreciation of this is what makes it easier to understand how sciensts decades ago were able to isolate, document, and understand salts in general, or other compounds and elements.

In my view, understanding how scientists decades ago were able to isolate, document and understand substances, will make it much easier to learn the facts required to analyze everything, identify a white powder, etc.

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Posted: 29 August 2007 01:35 PM   [ Ignore ]   [ # 34 ]
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CoryDuchesne - 29 August 2007 01:10 PM

Science popularizers and enthusiasts too readily impart theories, failing to illustrate the initial observations and experiments that justified the theories to begin with.  This is the major weakness of the scientific community, as there is a certain religiousness to how eagerly it’s members gobble up mere theory with questioning it’s basis.

Actually, it’s a strength of the scientific community. They don’t really care where the theory came from, so long as it is experimentally verified and accurate. Only historians care about where the theory came from. Scientists as a rule don’t care much about the history. What they care about are the experimental results. The theory could just as easily have come from Mars.

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Posted: 29 August 2007 02:00 PM   [ Ignore ]   [ # 35 ]
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dougsmith - 29 August 2007 01:35 PM
CoryDuchesne - 29 August 2007 01:10 PM

Science popularizers and enthusiasts too readily impart theories, failing to illustrate the initial observations and experiments that justified the theories to begin with.  This is the major weakness of the scientific community, as there is a certain religiousness to how eagerly it’s members gobble up mere theory with questioning it’s basis.

Actually, it’s a strength of the scientific community. They don’t really care where the theory came from, so long as it is experimentally verified and accurate.

The basis of a valuable theory is the experiment that has verified it.  There are far too many gung-ho secularists who have no interest in the initial experiments responsible for supporting a theory. 

Superstring enthusiasts are excellent examples of what I regard as the disease of secularism.

And when it comes to the theories that actually do have an experimentally verifiable basis, people are too often content to disregard the challenge of understanding the particular experiment, and instead believe an authority who merely asserts that a theory has been experimentally verified, without describing the actual experiment responsible for verification.  This isn’t always the case, but too often, it is.

Only historians care about where the theory came from.

This doesn’t make sense, because a theory comes from experiments.  Therefore, if you are concerned whether or not a theory is experimentally verifiable, then you are concerned about where the theory came from. 

Despite how it may appear to you, I’m actually not interested in the history of a theory, but rather, I just want to understand the initial experiments that verified the theories.  So far, nobody on this forum seems to know much about the particular experiments that have verified the most fundamental theory of chemistry, namely, the theory of elements.  Maybe they do.  I look forward to hearing from that person.

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Posted: 29 August 2007 02:11 PM   [ Ignore ]   [ # 36 ]
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I would disagree slightly with the implication that history is not very important to science. Though I don’t accept the purely relativist position that all epistemologies are equal, I do think history, social context, culture, and blind luck affect the questions scientists ask and the hypotheses they are likely to formulate, and they are not as individuals immune to comfirmation bias and the other ills that beset any attempt to undertsand what is true. Though the method ultimately will out the truth, there can be long periods of error driven by cultural and historical circumstances, and I think it is instructive for scientists to be aware of this and the history of their own process. Social Darwinism is a discredited, inappropriate application of some of the theories of natural selection that emerged in a cultural context in which brutal competition was seen as the natural order and in the long term a good thing. Darwin may have been helped to his insights by the same set of ideas about competition that led to the misapplication of his theories and to particularly vicious forms of capitalism. It is instructive to recognize that Darwin, as a product of his cultural mileu, may have come to some parts of his ideas by a route that was not independant of history and culture and that also led to many bad ideas. However, unlike these bad ideas, his have been refined and proven to work through the method of science, which can weed out the mistakes and leave the core of truth behind given enough time.


I do agree that if a hypothesis or a theory has repeatedly provided verifiable predictions and forms the basis for a large amount of subsequently successful cycles of theorizing and experimentation, its historical roots aren’t really relevant to evaluating its truth. If it works, it’s true whether it was conceived historically by fortuitous mistake or brilliant insight.

[ Edited: 29 August 2007 03:24 PM by mckenzievmd ]
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Posted: 29 August 2007 03:08 PM   [ Ignore ]   [ # 37 ]
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CoryDuchesne - 29 August 2007 02:00 PM

The basis of a valuable theory is the experiment that has verified it.  There are far too many gung-ho secularists who have no interest in the initial experiments responsible for supporting a theory. 

Superstring enthusiasts are excellent examples of what I regard as the disease of secularism.

Superstring theory hasn’t made any verifiable predictions yet. That is why it is considered at best a proto-scientific theory at this point. Now what that has to do with secularism I haven’t the vaguest idea.

CoryDuchesne - 29 August 2007 02:00 PM

This doesn’t make sense, because a theory comes from experiments.  Therefore, if you are concerned whether or not a theory is experimentally verifiable, then you are concerned about where the theory came from. 

Theories come from many places, only some of them are experimental.

The argument that the history of something makes it true or false is called the genetic fallacy. Now, we can often tell quite a bit about how a theory was founded, about what experiments were crucial to its acceptance, et cetera. And sometimes that can help us to judge whether a theory is plausible. But really that doesn’t have anything to do with whether the theory is true or not. The only thing that matters to the validity of the theory are its experimental implications, and whether those are verified by experiment or not.

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Posted: 29 August 2007 06:36 PM   [ Ignore ]   [ # 38 ]
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Back to how they knew the elements existed.  Large parts of it arise from the observation that when you put two electroded into a sodium chlorise solution you get hydrogen gas and chlorine given off and it was known that you could make sodium chloride by inverting a gas jar full of chlorine over a slightly warmed piece of sodium.  It was recognised that in electrolysing this solution you could split it up into one of its original starting materials (chlorine) and that you couldn’t actually split chlorine up into two different substances. They then tried the same on many different metal salts and found that they usually could split them up in to the pure metal and the molecular form of whatever anionic species it was combined with.  It was found that you couldn’t split the metal or the elemental form of the cationic species into two different substances so they were clearly made of atoms of only one type of element whereas the salts were compounds of two types (or sometimes more) types of element.  Do this to enough solutons of enough different salts and you eventually find most elements.  Hydrogen was found because when you split sodium chloride into sodium and chlorine, the sodium initially forms at the cathode but (since sodium reacts readily with water), it dissolves splitting the water into hydrogen gas and hydroxide ions (forming a sodium hydroxide solution), but they found they couldn’t split the hydrogen into other substance.  Oxygen was found because if you keep a plant under a bell jar and try to kill it by starving it of oxygen, it not only thrives (if kept in sunlight and watered), but also if you put a mouse under the bell jar with it, that survives also (whereas it doesn’t if you keep it under there without the plant to produce oxygen).
So a vast number of different elements can easily be discovered using nothing more sophiticated than a nine volt battery, two electrodes, water and a salt. 

As to discovering the mass numbers, well, you weigh out a certain mass of one element and see how much of another of known mass number, it reacts with.  I would guess the first mass number would have been known as a result of an experiment akin to the closed crucible method of burning magnesium.  You weight the magnesium, evacuate the crucible of any air it may contain and weigh the whole thing in vacuo.  Allow as much pure oxygen (this is easy to produce) bit by bit as it takes to burn the magnesium fully.  reweigh the container (containing the magnesium oxide) and repeat several times for different masses of magnesium.  Use these starting and finishing weights to ascertain what mass ratio of magnesium to oxygen is just enough for each set of results.  And work it out from there.  I can think of a valid method for doing this, but I don’t know if it’s how the early chemists found out mass numbers.  Atomic numbers are much harder to work out (they are just the number of protons in the nuclei of the elements) so they were figured out later (after the periodic table was pretty much completed to the extent it is today.

Your homework assignment is to go and research how they discovered the atomic numbers (I can think of an easy way - hint they actually had periodic tables to help them by this stage) and explain how they did it to everyone who has joined in this thread.  It’s just a bit of quid pro quo, if you will.

[ Edited: 29 August 2007 06:40 PM by narwhol ]
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Posted: 29 August 2007 07:33 PM   [ Ignore ]   [ # 39 ]
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dougsmith - 29 August 2007 03:08 PM
CoryDuchesne - 29 August 2007 02:00 PM

The basis of a valuable theory is the experiment that has verified it.  There are far too many gung-ho secularists who have no interest in the initial experiments responsible for supporting a theory. 

Superstring enthusiasts are excellent examples of what I regard as the disease of secularism.

Superstring theory hasn’t made any verifiable predictions yet. That is why it is considered at best a proto-scientific theory at this point. Now what that has to do with secularism I haven’t the vaguest idea.

Many secularist-types think superstring theory is valuable and exciting and this mentality is very connected to the mentality that readily accepts theories not because they are interested in doing experiments or having an understanding of the experiments that verify the theories they enjoy, but simply because an authority claims the theories have been verified and are ok to believe in.  The mentality of many secularists is a religious one, best exemplified in superstring theorists, and also exemplified in people who blindly accept scientific theories without understanding the experiments that verify them. 

The argument that the history of something makes it true or false is called the genetic fallacy.

Ok, but nowhere in this thread have I implied that history makes a theory true or false.  I’m interested in digging up the experiments that have verified the elements.  Who, when, and where, truly is trivial, but it’s useful to know these things at first, as that info might lead to a description of the experiments that verified the theories.  I guess my interest in starting with the individuals who made history as a means of uncovering the experiments has been influenced by my enjoyment of reading how Rutherford detected the nucleus, or how Darwin observed the results of domestication in contrast with the observations of Malthus and Lyell.  I just expected to find some interesting anecdotes in regards to how certain individuals first detected elements. 

The only thing that matters to the validity of the theory are its experimental implications

Ok, starting now, I just want to know how the elements can be verified, period.  I’m not too interested in generalizations, I’m interested in a specific experiment, responsible for verifying a specific element.  At least for starters anyway.

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Posted: 29 August 2007 10:46 PM   [ Ignore ]   [ # 40 ]
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CoryDuchesne - 29 August 2007 07:33 PM

Many secularist-types think superstring theory is valuable and exciting and this mentality is very connected to the mentality that readily accepts theories not because they are interested in doing experiments or having an understanding of the experiments that verify the theories they enjoy, but simply because an authority claims the theories have been verified and are ok to believe in.  The mentality of many secularists is a religious one, best exemplified in superstring theorists, and also exemplified in people who blindly accept scientific theories without understanding the experiments that verify them. 

Like who? Which “secularists” are you talking about, and when did they claim these things?

And I don’t know what you mean by “blindly”. One must accept most of what one believes on trust—nobody has the time or knowledge to verify everything.

Indeed, this is a very odd claim. Who do you think is acting in a less blind manner than your “secularists”? The only other game in town are people who accept things based on faith—which is to say that not only do they accept things blindly, they wouldn’t even accept experimental disconfirmation if it came their way, and don’t care when they are shown it doesn’t exist.

CoryDuchesne - 29 August 2007 07:33 PM

Ok, but nowhere in this thread have I implied that history makes a theory true or false.  I’m interested in digging up the experiments that have verified the elements.  Who, when, and where, truly is trivial, but it’s useful to know these things at first, as that info might lead to a description of the experiments that verified the theories.  I guess my interest in starting with the individuals who made history as a means of uncovering the experiments has been influenced by my enjoyment of reading how Rutherford detected the nucleus, or how Darwin observed the results of domestication in contrast with the observations of Malthus and Lyell.  I just expected to find some interesting anecdotes in regards to how certain individuals first detected elements. 

Expected to find?

It appears to me that the people on this thread have had a large amount of patience to be basically giving you a short intro course into chemistry and its history. Perhaps we should emphasize that there is an enormous amount of information on all these subjects at your local public library. One can find a threadbare intro on Wikipedia; but if you are actually interested in finding out quite extensive information on Rutherford or Darwin, there are literally scores of books on each which should provide you with the information you want. But you do have to actually do some of the work on your own now.

CoryDuchesne - 29 August 2007 07:33 PM

Ok, starting now, I just want to know how the elements can be verified, period.  I’m not too interested in generalizations, I’m interested in a specific experiment, responsible for verifying a specific element.  At least for starters anyway.

You have already had some starters to this in the thread. But NB: there is no such thing as an experiment “verifying an element”. That is a nonsensical phrase. What a theory does is to make predictions about phenomena; the experiment verifies that the phenomena occurred, or notes that they did not occur. So, you predict that if element X is present, you will get phenomena Y. Then you run the experiment to see if Y occurs. If Y occurs, that is evidence that X was present. If not, not. This is the form of the evidentiary support for the theory that includes X.

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Posted: 29 August 2007 11:47 PM   [ Ignore ]   [ # 41 ]
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Doug,

Perhaps we should emphasize that there is an enormous amount of information on all these subjects at your local public library.  One can find a threadbare intro on Wikipedia; but if you are actually interested in finding out quite extensive information on Rutherford or Darwin, there are literally scores of books on each which should provide you with the information you want.

I’m satisfied with what I know about Rutherford and Darwin.  I think you misunderstood what I was saying in regards to those guys.  I meant that I had come to understand the theory of natural selection as well as the theory of the atom’s nucleus by reading about the experiments and observations that Rutherford and Darwin made.  Being interested in elements, I was half expecting to find similar anecdotes about the particular experiments which gave support for the theory of elements.   

there is no such thing as an experiment “verifying an element”. That is a nonsensical phrase. What a theory does is make predictions about phenomena; the experiment verifies that the phenomena occurred, or notes that they did not occur.

Well, I think you’re being a little too nit picky here.  The results of the experiment verify that there is reason to visualize elements in the way the theory suggests they should be visualized.   

So, you predict that if element X is present, you will get phenomena Y.  Then you run the experiment to see if Y occurs. If Y occurs, that is evidence that X was present.

So Y, verifies X.  And X is a theory.  Thus, the results of an experiment can verify(support) the theorized element.

And Doug, as for the other things about what I believe are the short-comings of secularism, that will need another thread.

[ Edited: 29 August 2007 11:53 PM by CoryDuchesne ]
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Posted: 29 August 2007 11:57 PM   [ Ignore ]   [ # 42 ]
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Mckenize, Narwhol, thank you for your recent replies.  I’ve hardly had any awareness of electrolysis hitherto, and searching about it has left me with a wealth of information to explore. 

I’ve yet to clearly understand the entirety of what you each said in your posts.  I will give them another read tomorrow and perhaps respond to take this further.

[ Edited: 30 August 2007 12:00 AM by CoryDuchesne ]
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Posted: 19 September 2007 07:55 PM   [ Ignore ]   [ # 43 ]
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Figured I’d try finishing what I started here.  After collecting more info and thinking, my original posts now seem unsatisfactory.  New questions have emerged:

“When did humans first succeed at willfully exploiting a common material via a clever technique, extracting a substance that we in the present age regard as an element?  What was this common material?  What was the technique?  And why did they value doing this?”

Various sources tell me that this was first done before the written word - over 50’000 years ago.  I have yet to visualize & understand exactly their method, but reportedly, they would burn wood in chambers purposely reduced of oxygen, and this would, for reasons I don’t clearly understand, produce graphite chunks of charcoal, which is essentially carbon.  They valued doing this because they would use this carbon/charcoal for cave paintings, and later would use it to manufacture metal.  Given that all life is carbon based, and that carbon is one of the commonest substances on Earth, it’s only natural that carbon was the first element manufactured, consciously valued and sought after. 

Interestingly, the vital key for unlocking subsequent elements, was carbon.  Carbon was like a key bestowed by the Gods, allowing humanity, for the first time, access to the elements categorized as metals, and those metals were the keys to unlock further elements.

The first (and easiest metal to manufacture) was copper, which was first produced 6000-10’000 years ago.  My understanding so far is that copper, or any metal, is like a particular juice contained in a rock (such a rock is regarded as an ‘ore’), and this juice is squeezed out of the ore by heating it in a way where carbon is used to act as a reducing agent, changing the oxidation state of the ore. 

I don’t really understand what I just said about carbon acting as a ‘reducing agent changing the oxidization state’ unfortunately.

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Posted: 20 September 2007 01:45 PM   [ Ignore ]   [ # 44 ]
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Hi Corey,

A reducing agent is a chemical that reduces an oxidised species.  Reduction is either loss of oxygen (e.g. Copper oxide (copper ore) becoming copper), gain of hydrogen or gain of electrons and its the opposite of oxidation (which can be either gaining of oxygen to become an oxide, loss of electrons or loss of hydrogen).  In this case,  Copper ore is copper oxide.  Carbon is an element
Copper oxide + carbon forms copper + carbon dioxide

In this case, the copper oxide has been reduced to copper by the carbon, so the carbon is called a reducing agent.

Conversely, the carbon has been oxidised to carbon dioxide by the copper oxide.  So the copper oxide is called an oxidising agent.

This happens because carbon is more reactive than copper so it is more likely to form compounds whereas copper is more likely to be stable as an element (because it is less reactive than copper).  When a more reactive species displaces a more reactive species (as carbon displaces the copper from the copper oxide, to form an oxide of its own), it is called displacement.

Humans have been doing this ever since they firstt noted that you could make a pure metal (copper) by burning charcoal in the presence of some rocks of copper ore (malachite = copper oxide).  It was valuable for making tools and weapons.  much better than just using the rocks themselves.

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Posted: 20 September 2007 09:25 PM   [ Ignore ]   [ # 45 ]
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There is an on-line company called, “The Teaching Company” that packages various professor’s lectures from around the US in audio and/or video for sale.

I have read many positive reviews about some of their titles and others have been panned.  I have not read a review of this one, which would seem to answer some of your questions:

http://www.teach12.com/ttcx/coursedesclong2.aspx?cid=1200&id=1200&pc=Science and Mathematics

These titles go on sale quite regularly for instance that $374 price tag can come down to as little as $59.00.

Personally, I’m waiting for their dual packaging of, “The Joy of Thinking and The Joy of Mathematics” to go back on sale as I missed it the last time.

PBS has a number of science DVDs that you should be able to rent from Netflix (if you are in the US) or RogersVideoDirect (if you are in Canada) that may have more answers for you.  I know we quite enjoyed, “Newton’s Dark Secrets” and at some point I saw a great documentary on chemists in the 1700s to 1800s (I read and watch a LOT and sometimes miss or forget the titles, sorry) that documented a French chemist team of husband and wife who were experimenting right before the French Revolution as well as Michael Faraday and beyond.

I think that most modern day chemistry derides from humankind’s quest for gold and metals that would give them a leg up in war…as did bronze in the Bronze Age.

Anne

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