How to identify an unknown element?

[fredreload]

If you do not know an element's atomic number, can you infer it from its bonding structure with other molecules? Or is there other ways of identifying an element?

[Sensei]

Quote

How to identify an unknown element?

Scientist with the right equipment can do it using mass spectrometer.

Elements can be identified by their spectral lines. This method is used by astrophysicists it learn what is composition of stars.

 

[OldChemE]

or, if you don't want to go the mass spectrometer route basic inorganic chemistry works too-- pick up any good college level text on the subject and you will find lots of help.  Be warned, however, inorganic chemistry is fun but it is also the hard way-- that's why mass spectrometers are used so much these days.

[studiot]

4 hours ago, fredreload said:

If you do not know an element's atomic number, can you infer it from its bonding structure with other molecules? Or is there other ways of identifying an element?

This is a very strange question, since it implies you know a great deal more than you have said.

How do you know its bonding structure and what do you mean by this?

Are you trying for qualitative analysis rather than quantitaive analysis.
That is do you just want to identify the constituent of something rather than its proportions?

Do you have no clue as to the element or do you simply want to distinguish between one of several known alternatives?

+1 to Sensei for picking two good, if expensive alternatives.

Simpler methods might be to use an ignition tube test or a flame test.
But check to make sure if the stuff you want to test is not hazardous.

[fredreload]

Sensei is correct in stating that a spectrometer could work, because the spectrum of light reflected is different for each element.

[hypervalent_iodine]

1 minute ago, fredreload said:

Sensei is correct in stating that a spectrometer could work, because the spectrum of light reflected is different for each element.

If you already knew that, why did you ask the question?

[swansont]

On 5/19/2018 at 11:45 PM, fredreload said:

If you do not know an element's atomic number, can you infer it from its bonding structure with other molecules? 

There are elements that get substituted in molecules owing to the similar chemical nature. Especially if they are in the same column of the periodic table.  Strontium, for example, replaces Calcium in bones for this reason (meaning it stays in the body a long time, which is why radioactive Strontium is such a danger)
 

So the answer there would be "not always"

[fredreload]

On 2018/5/25 at 12:50 PM, hypervalent_iodine said:

If you already knew that, why did you ask the question?

Well I didn't know that, my mind was on the workings of a nanomachine and how it could break down bonds. As you know enzymes and catalysts works by having the correct molecular pieces placed inside them. Even then they could be disabled by inhibitors. Point is you could use an electrical charge "cage" to grab the correct element, but it would be easier with a spectrometer? Well, not something I could visualize at that scale

[YaDinghus]

9 minutes ago, fredreload said:

Point is you could use an electrical charge "cage" to grab the correct element, but it would be easier with a spectrometer? Well, not something I could visualize at that scale

That is one possible way. Afaik that is similar to how many antidotes to heavy metals work: Chelat ligands like EDTA bind to the heavy metals stronger than the enzymes they impair, and are then transported out of the blood stream via the urinal tract. Caution: the ligands themselves usually don't carry a net charge, there is a charge imbalance in the molecule that binds to the free orbitals on the heavy metal. There are however much more complex mechanisms at work when you want to imitate an enzyme - a friend of mine is actually studying the quantum aspects of catalytsis at the University of Bayreuth, Germany. 

[hypervalent_iodine]

51 minutes ago, fredreload said:

Well I didn't know that, my mind was on the workings of a nanomachine and how it could break down bonds. As you know enzymes and catalysts works by having the correct molecular pieces placed inside them. Even then they could be disabled by inhibitors. Point is you could use an electrical charge "cage" to grab the correct element, but it would be easier with a spectrometer? Well, not something I could visualize at that scale

Perhaps you could explain this a little more scientifically, as I am having trouble trying to figure out what you are talking about.

 

34 minutes ago, YaDinghus said:

That is one possible way. Afaik that is similar to how many antidotes to heavy metals work: Chelat ligands like EDTA bind to the heavy metals stronger than the enzymes they impair, and are then transported out of the blood stream via the urinal tract. Caution: the ligands themselves usually don't carry a net charge, there is a charge imbalance in the molecule that binds to the free orbitals on the heavy metal. There are however much more complex mechanisms at work when you want to imitate an enzyme - a friend of mine is actually studying the quantum aspects of catalytsis at the University of Bayreuth, Germany. 

Perhaps I am misunderstanding what you are talking about here, but ligands that bind to metal centres frequently are charged species. EDTA for example, is generally in charged form (Acetate groups posses a negative charge) when it chelates to metal centres.  

[YaDinghus]

14 minutes ago, hypervalent_iodine said:

EDTA for example, is generally in charged form (Acetate groups posses a negative charge) when it chelates to metal centres

I might have remebered falsely. Thanks for correcting me