GENIUS FORUMS

I'm going to start by asking a question related to the evolution of the modern day periodic table of elements

Reportedly, the current standard table contains 117 confirmed elements.

The current table's origin is generally credited to the table invented by Russian chemist Dmitri Mendeleev in 1869, however, it is said that earlier precursors of the periodic table existed, before Mendeleev's.

That being said, does anyone here have any idea how many elements Mendeleev knew about back in 1869? How many elements had been discovered by then?

Also, at what point did the meaning of the word 'element' change? For instance, I know Aristotle regarded 'water' as an element. But at what point was water no longer considered an element, instead being regarded as a substance comprised of elements?

I'm guessing that substances like rain water, salt crystals, sucrose (sugar) crystals, quartz crystals, soot, any mineral crystal and gold were fundamental, vital objects of contemplation in regards to the development of chemistry as a science - however, I want to know how substances like rain water, salt crystals, sucrose crystals, etc, had come to be regarded as things comprised of smaller elements.

So does anyone know who the individuals were that were responsible for changing the meaning of the word element, allowing for substances like water and sugar to be regarded as comprised of elements, as well as allowing for the periodic table, as we know it, to develop?

In case any of you find the nature of my inquiries above to be a bit trivial, consider this:

I'm actually not primarily interested in 'who' made the discovery/invention, or even necessarily 'what' was discovered/invented. My main interest is knowing how break-through discoveries and inventions were made. And of course, in such a venture, knowing 'what' was discovered/invented is vital, and knowing the individual who did the discovery helps quite a bit in terms of understanding how the discovery happened.

So my interests are not as trivial as they may appear, albeit, even with that considered, you may still find my interests trivial. In that case, one of us is likely the greater soul. ;)

Ok, so I found some interesting leads, ones which have refined my inquiry a bit:

Phlogiston Theory

From Wikipedia:

"Traditionally, alchemists considered that there were four classical elements: fire, water, air, and earth. In his book, Johann Becher postulated the phlogiston theory, eliminating fire and air from the classical element model, replacing them with three forms of earth: terra lapida, terra mercurialis, and terra pinguis."

^ This interests me because it kind of represents the nascent creature of modern chemistry, struggling to peck it's way out of the egg. (the egg representing the greek conception of the four elements, which served as the foundation of chemistry up until that point)


And then:

Antoine Lavoisier

From Wikipedia:

"Lavoisier disproved the phlogiston theory, due largely to recognizing and naming oxygen (1778) and hydrogen (1783)"

^ How did he recognize oxygen and hydrogen?

Ok course, I will seek an answer for this, and when I find it I will evolve this thread a bit further, but if you think you can help along my inquiries, then by all means.

I like where you're going with this. And how you're think about it. However, I don't understand why you would want to learn about the people who invented or discovered these things. It's not like you will be able to understand how and why, they thought the way they did, by learning about their names, upbringing and so on. The only benefit I see for this, would be to show off with your useless knowledge, or maybe it's not so useless...Maybe, you can use it the same way mnemonics are used. I would think you would have your hands full, with how these things work and the way they do and why they work the way they do, instead of who (invented them) and how they were discovered. Reminds me of the "fairytale", about Newton sitting under a tree... Who cares, that doesn't teach you much. If you have the desire, learn the basics. Focus on the function (how does it work and why?) and what effect does it produce and make sure you understand this, as thoroughly as possible. Hell, read about the scientists and inventors, this may aid in a better understanding, whatever works for you. All the more power to you!

I wrote something earlier, but it was trivial and wouldn't help you in anyway. I think you saw it. I basically wrote it, because I realized I knew a little bit about your topic, so I wanted to show off whatever little information I knew. It became embarrassing, so I deleted it. One other thing, while learning the basics, I think it's a good idea to read the more advanced work, also. Even if, you don't understand it, at first. You will eventually.

Learning about the four elements, is like learning about the earth being flat. It doesn't help. If anything, it makes us realize how wrong we may be, when the more advanced human race discovers our mistakes and so on.

You probably know all this. The only reason I'm posting, is for my selfish reasons and inadequacies. Mind you, it still has its benefits. No matter how minuscule.

Btw, why are you so interested in this? Chemistry is the bases for EVERYTHING, so there's no surprise there, I'm just wondering...

RalphPL wrote:I like where you're going with this. And how you're thinking about it. However, I don't understand why you would want to learn about the people who invented or discovered these things. It's not like you will be able to understand how and why, they thought the way they did, by learning about their names, upbringing and so on.

I'm more interested in understanding what the observations and attitudes that caused humans to assume things work in such and such a way. Knowing names is helpful insofar as there are articles about these individuals that illustrate an approximation of their thinking processes, conflicts and accidental discoveries. (although, I agree that the apple falling on Newton's head is pretty lame and uninsightful)

When I learned about how the theory of Darwinian natural selection was developed, I found it very useful to see how vital of an influence the geologist Lyell was on Darwin. The reasons for why Lyell developed his theory the way he did was based on observations he made. Interestingly, he was very against the idea of evolution, and he developed his theory in order to defend himself against it. However, he was such a good observer, and his theory was based on such keen observation, that his geological theory ended up inadvertently giving Darwin the insight and clarity he required to sketch out his theory of natural selection. How a theory is developed interests me more than the theory itself.

The only benefit I see for this, would be to show off with your useless knowledge, or maybe it's not so useless...

Honestly, this has nothing to do with showing off. It's just something I'm interested in.

If you have the desire, learn the basics. Focus on the function (how does it work and why?)

But you see, I'm more interested in understanding what the observations and attitudes were the caused humans to assume things work in such and such a way. For now anyway.

I think it's a good idea to read the more advanced work, also. Even if, you don't understand it, at first. You will eventually.

Yeah, I don't like this approach. When I'm hungry for more advanced stuff, I will go after it. Right now I'm interested in the factors which caused people to think the way they did. Psychology is one of my major interests, so my approach to chemistry is feeding my interest in psychology as well.

Learning about the four elements, is like learning about the earth being flat. It doesn't help. If anything, it makes us realize how wrong we may be

I'm not interested in learning about the four elements. I'm interested in learning about the sorts of observations which caused people to feel confident about changing the word 'element' to mean something other than water, fire, etc.

Btw, why are you so interested in this?

I'm interested in getting a clearer understanding of the nature of knowledge. How it is we know and the ways we go about knowing interest me more than what we know.

After you brought up this area of thought before, I started thinking and I realized that there is actually a PBS documentary in existence that peers into the life of the creator the first rudimentary periodic table. I seen bits of it, and from what I remember his insights came to him as burst of ephinies as he did his experiments. So he confirmed and sorted the properties of the elements that were interacting, but his insights never came as a result of actually observing separate atoms, only the behavior of those atoms in relationship when reacting with each other. I also remember that as he did his experiments, he created small square pieces of paper that he put out in front of him on the floor, and he labelled them as he discovered a new element in his experiments, and he organized the square pieces of paper according to their unique properties such as atomic mass, positive or negative charge, gas, solid, or liquid and so on.

I also found a link to a book that could provide some detailed answers of these early discoveries -
http://www.amazon.com/Last-Sorcerers-Al ... 030&sr=8-1


And if you discover the reasoning or scienific methods as to how they came to these first discoveries of the elements, post your findings here because I'm rather curious myself.

http://www.wou.edu/las/physci/ch412/perhist.htm

you might find this interesting

Deep stuff. Keep us posted.

Figured I'd try finishing what I started here. After collecting more info and thinking, my original post now seems 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 was comprised of carbon. They valued doing this because they would use this carbon for cave paintings, and later would use carbon 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.

The first (and easiest metal to manufacture) was copper. My understanding so far is merely analogical: 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.

Cory wrote:

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

Here is a hypothesis, ore or parent rock is mainly composed of silicate minerals, which translates into large amounts of silicon and oxygen bounded together. When Carbon is heated, perhaps it becomes more reactionary, and I believe carbon has a 2+ charge, which could react with the oxygen (2- charge) in the silicate minerals or ore, which could cause it to break down or lose electrons, which could cause the metals to be separate from the parent rock.

However, this is just a guess based on some of the geo-chemistry I remember from my intro geology class, can any chem expert confirm this?

Ryan Rudolph wrote:Cory wrote:

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

Here is a hypothesis, ore or parent rock is mainly composed of silicate minerals, which translates into large amounts of silicon and oxygen bounded together. When Carbon is heated, perhaps it becomes more reactionary

Not quite sure how to visualize carbon being reactionary. Can you be more descriptive?

and I believe carbon has a 2+ charge, which could react with the oxygen (2- charge) in the silicate minerals or ore, which could cause it to break down or lose electrons

Again, this is another thing that, unless I can visualize it, means very little to me. Are we talking about some parts of the ore becoming liquid and other parts becoming gas?

which could cause the metals to be separate from the parent rock.

Does the separation occur due to the silicon and oxygen becoming gas, rising up, and the metal becoming liquid, falling down and gathering in a pool?


I also want to back track and examine something more fundamental I mentioned in my previous post:

Cory wrote: 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 was comprised of carbon.

I think it would be worthwhile to understand how the primitives manufactured carbon, given that it was likely the first of the elements to be harnessed. On a descriptive level, from what I can visualize, carbon perhaps results when the elements comprising wood (not sure how many), due to heat, transform into gas, separating from the wood, and thus, what remains is no longer wood, but instead, is carbon, which apparently is resistant to being turned into gas.

^ Purely speculative. I'm just trying to set an example of what I'm looking for - - not so much explanations(which too often are just symbols which do not correspond with anything I can imagine), but visual descriptions of the process.

Cory wrote:

Not quite sure how to visualize carbon being reactionary. Can you be more descriptive?

Chemists heat substances up because it increases the chances and frequency of reaction. At normal temperatures, many substances move so slowly that they rarely contact each other, and they rarely react, but if you heat them up, there are more collisions with the other substances at higher speeds, and therefore more reactions as well.

Cory wrote:

Does the separation occur due to the silicon and oxygen becoming gas, rising up, and the metal becoming liquid, falling down and gathering in a pool?

That sounds the most likely, heavy elements like metals usually always stay in a solid or liquid form from what I remember from chem. class. It is only your lighter elements that can turn into gases.

Ok, well with that being said, let me backtrack to this:

Ryan wrote: Here is a hypothesis, ore or parent rock is mainly composed of silicate minerals, which translates into large amounts of silicon and oxygen bounded together. When Carbon is heated, perhaps it becomes more reactionary, and I believe carbon has a 2+ charge, which could react with the oxygen (2- charge) in the silicate minerals or ore, which could cause it to break down or lose electrons, which could cause the metals to be separate from the parent rock.

If I understand you correctly, the ore is comprised of an aggregate of elements(silicon, oxygen, copper, others?), and heat applied to the ore loosens the grip each element has on the other. That being said, am I right to intuit that the elements comprising the ore, vary in reactivity? I ask because, if carbon is a 'reducing agent' then that seems to imply that, during smelting, the carbon is reducing the ore by taking possession of an element (elements?) that once comprised the ore. The elements that the carbon steals, are the ones that are most reactive. Carbon doesn't take possession of copper because copper is the least reactive. Oxygen I'm guessing is the most reactive.

For instance, 'carbon dioxide' is carbon + oxygen. So it would make sense that the ore becomes reduced because oxygen, with increased temperature, most easily reacts, developing some sort of aversion to its condition in the heated ore, and thus develops a desire to escape into a less stressful situation. E.G., coupling up with carbon might be more romantic... ;)

Likewise, the carbon, with increased stress(temperature), develops an aversion to it's lone wolf independence, and so it too, like oxygen, becomes attracted to coupling up, given it dislikes the stress of high temperature. The relatively more feminine carbon and oxygen, due to stress, escape from the pressure of their lifestyle by binding together and floating away like fools toward the sky into happiness. The oxygen escapes from an unhappy, stressful marriage, while the carbon escapes from dislike of being alone.

In the meantime, the more masculine copper, due to lower reactivity, as it heats up, tends to become increasingly individualized, gathering mass, sinking in aloneness, rather than rising toward doom in marriage.

The question is, what happens to the silicon? How does it separate from copper? Does it escape as gas?

I'd also like to get clear on how many elements comprise your typical ore, and what the ratios are. My guess is that copper, or generally speaking, metal, comprises a low percentage of it's ore.

^ It seems that what I said above implies that some elements are more feminine than other elements. The more feminine the element, the more reactive it is, and the more reactive it is, the more readily it pairs up with other reactive elements. Perhaps too, the more feminine/reactive an element is, the more readily it turns into gas.
Whereas the more masculine an element is, the more resistant it is to turning into a liquid, and when it does turn into a liquid, it is more resistant to turning into a gas.

This brings to mind some two chemistry concepts that seem to be very related to each other, yet opposite to each other.

a) Chemical Synthesis
b) Chemical Decomposition

When it comes to smelting ores, it appears that decomposition requires synthesis. Without it, there can be no decomposition, only a loosening up.

Cory wrote:

When it comes to smelting ores, it appears that decomposition requires synthesis. Without it, there can be no decomposition, only a loosening up.

Yes, this makes sense considering that the most fundamental chemical equation is A +B = C + D meaning that when two substances react, elements from B switch with A resulting in two different substances. Synthesis is Decomposition.

nice analogies btw, and I thought of something very ironic while reading your descriptions, it seems to me that most elements are naturally feminine outside human influence, meaning they are always reactive under certain circumstances. Some elements may become masculine, meaning they will become free independent ions, but only temporarily. However, there are a few rare naturally masculine elements, which do not usually react with most things under any circumstances. The two I’m thinking of are GOLD and DIAMONDS (compressed carbon over thousands of years). Consider that… you have two elements that do not react with anything very well (masculine), but their outward appearance is very feminine, and ironically, humans use these two elements for very feminine purposes…hahaha…

The birth of diamonds is an interesting story as well. You have dark carbon, which structurally is quite mediocre and ugly, but when put in an extreme environment, (high temperatures and pressure), it manifests into diamonds, which structurally is quite magnificent. Also, perfection in a diamond is measured by how masculine it is, meaning an impurity is basically carbon atoms that have reacted with something, whereas a perfect diamond consists of only independent carbon atoms.

At this point, I can't help but find myself focusing on how humans first determined the constituents (and thus, the value) of the ore's they sought. For instance, using the simplest, most primitive means possible, how do I personally identify a column of rock that has metal in it?

This guy attempted to smelt an ore the old fashioned way in hopes of extracting some copper, just for fun. If you scroll down to the bottom of the page, you'll see he failed in his mission.

He writes:

after two days of fairly hard work, we got enough copper for maybe 3 BBs. What went wrong? Currently we think it was the ore. None of us are geologists; "we just found some greenish rocks."

Although I admire his efforts and intend to glean as much as I can from his website, I find his efforts at explaining his actions to be a bit opaque.

For instance, at the very top of his site he writes:

The basic idea (of smelting) is pretty simple. Most metal on the planet isn't in metallic (or native) form. They appear in ores as various oxides, silicates, sulfides, etc. To get a useful metal, the other elements have to be removed. This is done by getting the ore very hot in a reducing atmosphere, so that the spare carbon can grab all the oxygen from the ore. (This is the general case for a simple oxide. Roasting before smelting can help turn some of the other compounds into oxides. It also makes the ore easier to crush.)

Does anyone know what he's talking about in the tail end there?

What's the difference between roasting an ore & and applying the sort of heat to 'smelt' it?

Later he writes:

For improved smelting, you also need a flux. The ore will always have lots of stuff in it that you're not interested in, generically called gangue. In lots of copper ores the gangue is primarily silica which melts into slag at a high temperature. To get good results you want a very liquid slag, so that the copper can move through it easily and form a nice plano-convex ingot at the bottom.

Any idea what he means near the tail end here? I can picture the shape of a plano-convex (it's like a contact lens, sitting like a bowl right side up) But I'm not sure if I'm supposed to visualize the copper as a liquid (I would think so, but on 'ingot' typically refers to a solid block or nugget of metal).

Why does the copper move through the slag? I can see how copper (turned to liquid) might 'gather' in the middle of the slag like the bulls eye on a dart board.

Also, I don't understand the whole 'plano-convex' thing, since it implies a lower elevation in the middle, with a gradual rising elevation around that sunken middle. It baffles me why this phenomena would occur. Is his attempt at describing just bad? Or am I just being dense here?

Cory wrote:

For instance, using the simplest, most primitive means possible, how do I personally identify a column of rock that has metal in it?

Using many visual location techniques. For instance: if you wanted to find gold, you need to know the types of rocks that gold commonly arise with. For instance: quartz veins in igneous plutons are common places to find gold. Metals only solidify at a certain temperature and depth within the earth, so they commonly only arise with certain types of rocks that also solidify at that same temperature.

Many times metals have different methods of extraction from the parent rock, and these methods can differ in complexity and expense depending on the metal the exploration team is looking for.

If you study geology in university, the 3rd and 4th year courses teach all the common techniques to find some of the more commercially viable metals. Questions such as, what biological environments to seek out, and what type of rock formations to look for, are addressed for each metal and mineral that is of necessity in society.

Some metals have such a labour-intensive extraction process that hired geologists need to locate enormous-sized deposits just to make the venture profitable for the exploration company.

For instance: My uncle was forced to sell all his exploration equipment, worth over 1 million because the area he choose didn’t end up having as much gold as he calculated so he didn’t make a profit, and he was forced to sell to pay off the debts that he accrued.

Cory wrote:

Why does the copper move through the slag?

The copper will probably be slightly less vicious than the slag at that temperature, and therefore distinct boundaries will form between the silica and the copper, giving the opportunity for the copper to be extracted.

Metals and minerals have different solidification temperatures, so applying the same amount of heat to two different types of material will not cause the same degree of melting.

The various metals have different types of patterns or paths of separation as they liquefy and separate from their parent host, and that is why copper takes a sort of planeo-convex shape as it sinks to the bottom, as it is more dense as well.

When you pick up a rock, and see many different minerals inside, all of those minerals solidified at slightly different temperatures, and so when you heat the rock up, depending on the temperature, some substances will become liquid right away, and others wont until you apply more heat.

Here is a good chart that I used to use in geology, it illustrates how the rocks with a higher silica content melt at lower temperatures. Lower melting minerals are called felsic rocks (to the right of the chart) and they are quite feminine. They are more transparent, they occur nearer to the earth’s surface, and they contain the highest amounts of Si02 (silica). Whereas the higher melting minerals are called mafic rocks, and they are more masculine, they are darker because they contain large amounts of heavier elements like Iron and Magnesium. They solidify at very deep in the earth, at extreme temperatures in the mantle.

Different types of Mafic and Felsic rocks are notorious for containing certain commercially viable minerals and metals that are needed as raw materials for civilization, so these types of graphs are essential for any geologist that is interested in the extraction process.

For instance: If an experienced geologist is looking for nickel, he knows he needs to find substantial deposits of certain types of metamorphic rocks (mafic) near the surface, so the first place he might start to survey is the Canadian Shield because that entire area is exposed metamorphic rock that used to be miles beneath the earth's surface in a magma state, but over large periods of time, tectonic activity forced it up to a certain degree, where it slowly solidified as its elevation increased, and erosion did the rest.