Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: omid on 07/11/2009 17:59:30

Title: Why does metalloids not form ions?
Post by: omid on 07/11/2009 17:59:30

Yesterday in omid's chemistry class omid learned from her teacher that metalloids don't form ions but when omid asked how come? teacher said  becasue it can't and that's it.


but what omid wana know is that if matalloids react with other metals and non metals then what are formed if neither an anion nor a cation? [:-\] [:-\] [:-\]

Title: Why does metalloids not form ions?
Post by: Bored chemist on 08/11/2009 13:50:15

The simple answer is that these elements tend to form covalent bonds.
The reason is that they have relatively high ionisation potentials and low electron affinities. (Some of the ionisation potentials are not all that high, but the ions formed would be quite big so they wouldn't pack closely into an ionic lattice. That makes it difficult to offset the energy needed to ionise the element against the crystal lattice energy)

Title: Why does metalloids not form ions?
Post by: omid on 09/11/2009 18:48:26

when a ionic bond is formed ions are produced but what are produced when covelent bonds are formed?  [???]

Title: Why does metalloids not form ions?
Post by: Bored chemist on 09/11/2009 19:06:17

Molecules.

Title: Why does metalloids not form ions?
Post by: omid on 10/11/2009 08:45:55

Quote from: Bored chemist on 09/11/2009 19:06:17

Molecules.

But ionic bonds also form  molecules

Title: Why does metalloids not form ions?
Post by: Bored chemist on 10/11/2009 19:37:49

Good point, but actually they generally form lattices.
It's dificult to show someone a molecule of, for example, sodium chloride. you can get a crystal of it but that's a collection of lots of ions.
On the other hand if I get some nicely crystaline carbon I can actually show you a single molecule.
Here is a picture of some molecules I would like for Xmas.
http://en.wikipedia.org/wiki/File:Cullinanroughpieces.jpg

Title: Why does metalloids not form ions?
Post by: omid on 13/11/2009 07:53:14

omid's chemistry book says
"the energy released form the combustion of 1 cm3 of liquid hydrogen is four times less then that of petrol. however the energy per gram is higher than other fuels, so liquid hydrogen is used as fuel in the booster rockets of the space shuttle"

Can you please tell omid what it really want to mention specially the bold parts [:-\]

Title: Why does metalloids not form ions?
Post by: lightarrow on 13/11/2009 13:34:45

Quote from: omid on 13/11/2009 07:53:14

omid's chemistry book says
"the energy released form the combustion of 1 cm3 of liquid hydrogen is four times less then that of petrol. however the energy per gram is higher than other fuels, so liquid hydrogen is used as fuel in the booster rockets of the space shuttle"

Can you please tell omid what it really want to mention specially the bold parts [:-\]

It means that you use preferably hydrogen in a rocket because you don't want to waste fuel just to lift it.

Title: Why does metalloids not form ions?
Post by: omid on 15/11/2009 20:24:49

omid had an exam on friday a chemistry practical exam.
it was to make a salt and calculate the %age yeild (ammonium nitrate (II)sulfate)
But the results for calculations'll be available on monday,  by the end of Experiment omid had some greenish liquid which is ment to form crystalls.
What type of crystals should omid expect to be formed if the experiment was all OK?

Title: Why does metalloids not form ions?
Post by: Bored chemist on 15/11/2009 20:36:24

I'd need a bit more information than that.
What did you add to what?

Title: Why does metalloids not form ions?
Post by: omid on 15/11/2009 20:40:08

Quote from: Bored chemist on 15/11/2009 20:36:24

I'd need a bit more information than that.
What did you add to what?

omid used the equation below;
(NH4)2SO4 + FeSO4 FORMS (NH4)2SO4.FeSO4.6H2O

enough or need more? [:-\]

Title: Why does metalloids not form ions?
Post by: Bored chemist on 15/11/2009 20:42:12

I think that if I did a search on the chemical formula of the product I would be able to find out a couple of things about it like the colour and perhaps a name (or two) for it.
What are you hoping to find out?

Title: Why does metalloids not form ions?
Post by: omid on 15/11/2009 20:45:47

Quote from: Bored chemist on 15/11/2009 20:42:12

I think that if I did a search on the chemical formula of the product I would be able to find out a couple of things about it like the colour and perhaps a name (or two) for it.
What are you hoping to find out?

While we all were done with the experiment all of omid's clasmates thought that omid is gona get the best results after looking at the product that is kept for crystalisation.
but the problem is that where we were suposed to test the solution (in the middle of experiment)on a red litmus paper omid's litmus paper didn't turned blue that why omid is wondering if her crystals will form or not?

Title: Why does metalloids not form ions?
Post by: Bored chemist on 15/11/2009 21:00:44

It's the nature of science that you dont really know what will happen until you have finished.

Title: Why does metalloids not form ions?
Post by: omid on 16/11/2009 10:18:26

Quote from: Bored chemist on 15/11/2009 21:00:44

It's the nature of science that you dont really know what will happen until you have finished.

Sorry BORED chemist but it didn't answer omid's question  [>:(]

Title: Why does metalloids not form ions?
Post by: lightarrow on 16/11/2009 15:14:54

Quote from: omid on 15/11/2009 20:40:08

Quote from: Bored chemist on 15/11/2009 20:36:24

I'd need a bit more information than that.
What did you add to what?

omid used the equation below;
(NH4)2SO4 + FeSO4 FORMS (NH4)2SO4.FeSO4.6H2O

enough or need more? [:-\]

Look for Mohr salt.

Title: Why does metalloids not form ions?
Post by: omid on 16/11/2009 17:56:29

Quote from: lightarrow on 16/11/2009 15:14:54

Look for Mohr salt.

omid had some very Dirty and nasty [:-\] crystals but omid's yeild was about 92%
so omid guess omid didn't go very wrong [:-\]