Naked Science Forum

General Science => General Science => Topic started by: goofkid on 16/12/2005 22:13:21

Title: Is that all?
Post by: goofkid on 16/12/2005 22:13:21
There are so many elements on the periodic table. And so many different compounds have been made and there are some that just don't mix with anything.

Have we tried all the possible combinations to come up with new materials in the periodic table?  [?]

If not, then y? Cuz we've know these elements for quite a long time.


Goofkid
Title: Re: Is that all?
Post by: DoctorBeaver on 16/12/2005 22:16:13
Every substance in the periodic table is an element. That means they are not combinations. All that can be done is to add extra protons (I think) thereby transforming them into heavier elements. Even so, I think I'm right in saying that there is an upper limit to how far that process can be taken
Title: Re: Is that all?
Post by: Soul Surfer on 16/12/2005 23:39:29
No we haven't found all the possible compounds made with the elements on the periodic table and I don't think we ever will, there's just too many.  remember there's only eight notes in the musical scale and people are still coming up with new tunes there's more than 90 elements.

Remember theres lots of physical properties as well as chemical ones for examples stengths of alloys between metals and weird structures like the things you need to get high temperature superconductors.

There are also some crystalline forms of materials that we are only just getting to grips with too  like the fabrication of diamond and its potential use as a semiconductor.

It is true that the list of elements and their isotopes is essentially complete and the basic properties of all the elements and the most obvious compounds have been well known for quite a long time.  

The next question is where are new and interesting discoveries likely to be made?

My guess is a lot innovations will come from handling and assembling atoms and molecules in precise structures.  This is sometimes called "nanotechnology" rather than chemistry.

Learn, create, test and tell
evolution rules in all things
God says so!
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 01:00:01
quote:
Have we tried all the possible combinations to come up with new materials in the periodic table?


I stand by what I said. The periodic table is a table of elements. Combinations doesn't come into it
Title: Re: Is that all?
Post by: Solvay_1927 on 17/12/2005 01:33:46
Eth, you've answered the question that was posed: "Have we tried all the possible combinations to come up with new materials in the periodic table?"

Ian, you seem to have answered a slightly rearranged question: "Have we tried all the possible combinations (of elements) in the periodic table to come up with new materials?"

To add to Eth's answer, here's a quote from Peter Atkins' book "Galileo's Finger" (a really excellent book I can recommend to anyone who's interested in a lay person's introduction to science):
"We now know about 110 elements ... There are sporadic reports of the discovery of elements up to [atomic number] 114, but some come and go, and [number] 113 is still missing ... The periodic table is still growing. Scientists are using particle accelerators to hurl the nuclei of one element against those of other elements, hoping that the two nuclei will merge and form the nucleus of an as yet unknownelement ... However, the nuclei [at these sizes] are very unstable, and the few atoms that are made have a very fleeting existence."

And to add to Ian's answer, there are TWELVE notes in the musical scale, not eight. [^]
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 01:46:01
quote:
And to add to Ian's answer, there are TWELVE notes in the musical scale, not eight


Only in Western music. Arabic, Indian etc have more
Title: Re: Is that all?
Post by: Solvay_1927 on 17/12/2005 02:20:06
Cleverclogs!
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 02:42:19
<smug grin>
Title: Re: Is that all?
Post by: neilep on 17/12/2005 03:00:32
There's some new elements in the bottom of my linen bin and it's developing it's own intelligence too !

Men are the same as women.... just inside out !!
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 03:30:48
Neil - Do you mean my socks are in your bin? I wondered where they'd gone!
Title: Re: Is that all?
Post by: neilep on 17/12/2005 04:11:06
Dear Dr Eth.

Please control your socks !

Should you be unable to manage the behaviour of your socks then I can recommend a good sock training management & coordination course for unruly apparel.

Men are the same as women.... just inside out !!
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 04:17:42
Do you have the URL for a sock-training website?
Title: Re: Is that all?
Post by: neilep on 17/12/2005 04:27:18
yes it's www.wetrainyoursocks.com   and  www.linenbininvaders.co.uk



Men are the same as women.... just inside out !!
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 04:29:36
http://www.yourehavingalaugh.com
Title: Re: Is that all?
Post by: neilep on 17/12/2005 04:39:28
You clicked on them though didn't you ?...c'mon...own up !!..and everybody else too...Hey !!..I even clicked on them ....just in case.....

Men are the same as women.... just inside out !!
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 04:45:23
I hate to disappoint you but no, I didn't click on them
Title: Re: Is that all?
Post by: neilep on 17/12/2005 04:52:01
quote:
Originally posted by DoctorBeaver

I hate to disappoint you but no, I didn't click on them



Meanypoos !!

I have to try and get some shut eye....my niece is getting married in few hours...my daughter is a bridesmaid...I suppose it would be nice to attend the wedding awake !!

night all....or...good morning...[:)]

Men are the same as women.... just inside out !!
Title: Re: Is that all?
Post by: DoctorBeaver on 17/12/2005 06:08:10
Aren't you a bridesmaid? [:D]
Title: Re: Is that all?
Post by: rosy on 17/12/2005 12:49:06
As a return to the original question "have we made all the possible compounds using the elements of the periodic table", the answer is a resounding NO!
According to my medicinal chemistry lecturer, a calculation by some people with time on their hands suggests that the number of possible "drug-like" molecules (I think this is as defined by Lipinski*) is so great that there are not enough atoms available in the universe to synthesise even one molecule of each. I admit to finding that fairly hard to believe, but Stuart Warren isn't the type to make stuff up/use dodgy sources, so I'm inclined to take his word for it...



*In general, an orally active drug has:
    * not more than 5 hydrogen bond donors (OH and NH groups)
    * not more than 10 hydrogen bond acceptors (notably N and O)
    * a molecular weight under 500
    * a LogP under 5
Title: Re: Is that all?
Post by: Soul Surfer on 17/12/2005 21:27:56
The preamble to goofkid's question made it perfectly clear that he was talking about chemical compounds and not elements and isotopes so i belive ~I answered the question that was posed.  We do I am really sure know all the stable isotopes that are possible.  The High atomic weight "island of stability" is there but its just an island of longer life that midst of the short lived radioactive isotopes.

Agree about the musical notes in western music of course but the point is just the same and I wasn't sure there were all that many music experts around [:-)]

Learn, create, test and tell
evolution rules in all things
God says so!
Title: Re: Is that all?
Post by: Solvay_1927 on 17/12/2005 22:07:32
Ian - you're right.  And yes, I know you answered the question that goofkid actually meant to ask.

And as for musical expertise, DrB is a composer.  (We're all waiting for him to upload some of his music onto the forum.) [;)]
Title: Re: Is that all?
Post by: another_someone on 18/12/2005 01:33:07
Beyond the original question is I suppose the question of how much do we actually need any longer to synthesise the various compounds in the real world, and how far computer modelling can do it for us?
Title: Re: Is that all?
Post by: goofkid on 18/12/2005 14:43:18
Thx all! so lemmy get this straight, the majority says there ARE many undiscovered materials that are just waiting... right? cool. [:D]

Goofkid
Title: Re: Is that all?
Post by: chris on 20/12/2005 08:40:51
quote:
Originally posted by DoctorBeaver

Every substance in the periodic table is an element. That means they are not combinations. All that can be done is to add extra protons (I think) thereby transforming them into heavier elements. Even so, I think I'm right in saying that there is an upper limit to how far that process can be taken


Just to clarify the above point, so there's no mistake, each element has its own atomic number which is equal to the number of protons in the nucleus. Adding a proton would therefore change one element into the next one in the series. In other words, hydrogen (1 proton) would turn into helium (2 protons).

But different forms of the same element can exist, and what distinguishes them is the number of neutrons in the nucleus. These alternative forms of the same element are referred to as isotopes. They are essentially the same element, but they contain different numbers of neutrons in the nucleus, and therefore have different atomic weights (referred to as the RAM or relative atomic mass), and physical properties, such as being radioactive.

For instance, hydrogen (sometimes called protium) has an atomic mass of 1. It consists of 1 proton in the nucleus and 1 electron whizzing around the nucleus. It has 2 other isotopes - deuterium, which has a mass of 2 and consists of a nucleus containing 1 proton and 1 neutron, and tritium, which has a mass of 3 with a nucleus containing 1 proton and 2 neutrons. This latter form is radioactive. In nature, the ratio of hydrogen to deuterium is about 5000:1.

Another example is carbon, which we use for carbon dating things - this involves comparing the ratios of carbon-12 to carbon-14.

Now here's a little conundrum for you. If you look at a periodic table the relative atomic mass for chlorine is 35.5. Given that neutrons and protons both weigh "1", how can you arrive at an atom which apparently has half a neutron in it ?

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx
Title: Re: Is that all?
Post by: Soul Surfer on 20/12/2005 10:32:26
The chemical atomic weights are those you find when doing experiments in the lab.  Most elements are mixtures of different proportions of the stable isotopes of that element.  It happens that chlorine cosists of two isotopes on weight 35 and the other 37 and about 25% is of the 37 so the mean atomic weight is 35.5.

Also the actual atomic weights of the individual isotopes are not precisely round numbers because the neutron and the proton do not have exactly the same mass (1.007593 for the proton and 1.008982 for the neutron) and you also have to allow a bit for the electrons and the binding energy of the neuleus  for example the atomic weight of hydrogen is 1.008142 and that of Helium 4.003873

Its also interesting to note that elements with an odd atomic number only tend to have one or at most two stable isotopes while even numbered ones have lots. Tin atomic no 50 has nine or ten!

Learn, create, test and tell
evolution rules in all things
God says so!
Title: Re: Is that all?
Post by: gsmollin on 20/12/2005 12:32:12
quote:
Originally posted by DoctorBeaver

quote:
And to add to Ian's answer, there are TWELVE notes in the musical scale, not eight


Only in Western music. Arabic, Indian etc have more



There are twelve notes in a tempered musical scale. Not all western scales are tempered, although that's the modern scale. The original western (Greek) scales were pentatonic, and if you singe acapella you are using one. But this wasn't supposed to be a music theory post. It's a good subject though.

"F = ma, E = mc^2, and you can't push a string."
Title: Re: Is that all?
Post by: chris on 20/12/2005 14:17:50
Soul Surfer - thanks for that very precise answer - I was hoping we'd catch some people out with that, but you didn't waste any time getting in there !

Given the content of your answer, I think you might be interested in one of the items in this week's Nature podcast, out tomorrow at 1800 (GMT) - http://www.nature.com/nature/podcast

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx
Title: Re: Is that all?
Post by: Soul Surfer on 20/12/2005 17:36:24
Thanks for the link must try to catch up with that.  Presumably you are the same chris.  Also note you are a UCL person although I went there and did physics in Harry Masseys time.  Paul Davies is a contemorary of me.

Decided to give up on reading Nature and Science last year 'cos I just didn't have the time what with New Scientist, Scientific American,  IEE, IOP, RAS and BAA stuff to read.   New Scientist also usually had articles on the stuff I was mainly interested in a week or two later and I could always backtrack at the library if I needed detail.

Learn, create, test and tell
evolution rules in all things
God says so!
Title: Re: Is that all?
Post by: chris on 20/12/2005 22:07:45
Yes UCL to do a neuroscence degree then Cambrdge for medcne and a PhD on gene therapy.

Chrs

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx
Title: Re: Is that all?
Post by: goofkid on 21/12/2005 22:03:23
O and another thing.

WHERE can i get elements from the periodic table so i can experiment with them!! This is important cuz i can't apply what i learned!
Thx [^]

Goofkid
Title: Re: Is that all?
Post by: Soul Surfer on 21/12/2005 23:22:47
They are all found in varying proprtions in most of the rocks and even sea water you just have to do a bit of chemistry to extract them. [:D]

Learn, create, test and tell
evolution rules in all things
God says so!
Title: Re: Is that all?
Post by: goofkid on 22/12/2005 10:16:37
quote:
Originally posted by Soul Surfer

They are all found in varying proprtions in most of the rocks and even sea water you just have to do a bit of chemistry to extract them. [:D]





O yea... maybe i could even go the the dead sea to get some NaCl, and then go all the way to Africa to get some Au, and then dig deep to get some C in hopes of finding diamonds! Yay!! I figured it out!


Goofkid
Title: Re: Is that all?
Post by: geoffspear on 22/12/2005 16:03:46
quote:
dig deep to get some C


You don't have to dig very deep to find carbon.  Every organic molecule (including the ones your body is made of) is built from carbon, among other things.