How to calculate the maximum charge of an atom or a molecule

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Discussion Overview

The discussion revolves around calculating the maximum charge of an atom or a molecule, exploring definitions, methods of calculation, and the implications of ionization. It encompasses theoretical and conceptual aspects of chemistry.

Discussion Character

  • Homework-related
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions how to calculate the maximum charge of atoms or molecules, referencing equivalent weight and providing calculations for Al, Ca, and O2.
  • Another participant seeks clarification on the definition of maximum charge.
  • A different participant suggests that an atom has maximum charge when fully ionized, but expresses uncertainty about whether this aligns with the problem's intent.
  • One participant emphasizes the importance of definitions while cautioning against becoming overly fixated on them, suggesting that the numbers calculated may relate to equivalent masses rather than direct charges.
  • It is noted that when atoms or molecules are charged, they are typically referred to as ions, and the charge can often be determined from their position in the periodic table.
  • Another participant mentions that in mass spectrometry, atoms and molecules are usually given a single charge through processes like electron bombardment.
  • One participant introduces the idea that accelerators and astrophysical processes can strip atoms down to their nuclei, which may not align with the original question.

Areas of Agreement / Disagreement

Participants express varying views on how to define and calculate maximum charge, with no consensus reached on the best approach or interpretation of the problem.

Contextual Notes

Some assumptions about the definitions of charge and equivalent weight may be missing, and the discussion reflects a range of interpretations regarding the relationship between atomic structure and charge.

HCverma
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Homework Statement


How to calculate the maximum charge of an atom or a molecule?
As we know the equivalent weight = atomic weight / maximum charge
Al, Ca and O2

The Attempt at a Solution


Al, E = 27/3 = 9
Ca, E = 40/2 = 20
O2, E = 16/2 = 8
I see on the books that the charges of Al, Ca and O2 are 3, 2 and 2 but
How to find the charges of Al, Ca and O2?
 
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HCverma said:
the maximum charge of an atom or a molecule?

And how is it defined?
 
Borek said:
And how is it defined?

Good question... I would say that atom has the maximum possible charge when it is fully ionized, but I have the feeling this is not the real goal of the problem...
 
Borek said:
And how is it defined?
Could you please tell me how to see my old threads?
 
Hoover the mouse over MY PF (upper toolbar), click "Your profile page" in the menu, look in the "recent activity" or "postings" tab.
 
I agree with 2 and 3. Definitions are important, but I recommend to not be hung up on them to the point of losing sight of acquiring essential ordinary ideas of chemistry.

Your numbers given by a division are something or other different from charges, probably to do with (related. concept of) equivalent masses (confusion?).

When an atom or molecule is charged it is usually not called atom or molecule any more but 'ion'.
Atoms or molecules may commonly lose or acquire electrons in their 'outer shells' mostly when they are surrounded by other stuff to and from which it is easy for them to lose or acquire them, expecially in aqueous solution or in crystals. The number lost or gained, and hence the charge acquired is easily calculated from knowledge of an element's position in the periodic table, or atomic number. At least this is true more often than not, the cases you first meet. E.g in solution, you get Al3+, Ca2+. Then for important heavier elements it's more complicated but not very, and rationalisable.

(Not in ordinary chemistry but in mass spectrometry, which us a somewhat specialised technique but which all chemists must know about, atoms and molecules are given a single charge (mostly) by electron bombardment etc.)

More than this not really profitable now IMO, you probably need to plough ahead in your general textbook without stopping here!
 
Last edited:
Probably not what you intended, but accelerators and various astrophysical processes may strip atoms to their bare nuclei.
 

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