LucyJl
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Bit stuck on a question n wondering If someone can help pls:

explain why the second ionisation energy of magnesium is greater than the first ionisation energy of magnesium

thankyouu
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ChemistryWebsite
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(Original post by LucyJl)
Bit stuck on a question n wondering If someone can help pls:

explain why the second ionisation energy of magnesium is greater than the first ionisation energy of magnesium

thankyouu
The answer would be similar for every element.
The first ionisation energy is the energy required to remove an electron from a NEUTRAL atom.
The second ionisation energy is the energy to remove an electron from an ion with a POSITIVE charge. There is a stronger attraction between this electron and a positive ion than between the first electron and an uncharged atom.
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ahussainxo
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In the positive ion, there are more protons than electrons. So the electrons are pulled in more strongly (by nucleus) to the positive charge. They are therefore more hard to remove so more energy is needed to remove that electron from an atom.
This is why successive ionisation energies increase. So the third ionisation energy would be greater than the second.

Hope this helps
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LucyJl
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(Original post by ahussainxo)
In the positive ion, there are more protons than electrons. So the electrons are pulled in more strongly (by nucleus) to the positive charge. They are therefore more hard to remove so more energy is needed to remove that electron from an atom.
This is why successive ionisation energies increase. So the third ionisation energy would be greater than the second.

Hope this helps

perfect thank you so much!! x
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LucyJl
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(Original post by ChemistryWebsite)
The answer would be similar for every element.
The first ionisation energy is the energy required to remove an electron from a NEUTRAL atom.
The second ionisation energy is the energy to remove an electron from an ion with a POSITIVE charge. There is a stronger attraction between this electron and a positive ion than between the first electron and an uncharged atom.
ahh thank you for your help
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charco
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(Original post by ChemistryWebsite)
The answer would be similar for every element.
The first ionisation energy is the energy required to remove an electron from a NEUTRAL atom.
The second ionisation energy is the energy to remove an electron from an ion with a POSITIVE charge. There is a stronger attraction between this electron and a positive ion than between the first electron and an uncharged atom.
Although this IS the accepted answer, it is not correct.

The stability of any electron is a function of the electrostatic attraction from the nucleus and the electrostatic repulsion from the other electrons.

Once an ion is formed there is less repulsion as there is 1 less electronand the electrostatic attraction from the nucleus remains the same (in the case of Mg and any other element in which we are dealing with the same energy level)

The net attraction is much greater than the repulsion, so more energy is required for ionisation.
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ChemistryWebsite
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(Original post by charco)
Although this IS the accepted answer, it is not correct.

The stability of any electron is a function of the electrostatic attraction from the nucleus and the electrostatic repulsion from the other electrons.

Once an ion is formed there is less repulsion as there is 1 less electronand the electrostatic attraction from the nucleus remains the same (in the case of Mg and any other element in which we are dealing with the same energy level)

The net attraction is much greater than the repulsion, so more energy is required for ionisation.
Are you recommending that answer to a student doing their AS / A level exams?
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charco
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(Original post by ChemistryWebsite)
Are you recommending that answer to a student doing their AS / A level exams?
No. As I explained the answer you wrote is the accepted answer.

But it is not correct.
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LucyJl
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(Original post by charco)
No. As I explained the answer you wrote is the accepted answer.

But it is not correct.
I can't lie the "correct" answer is so confusing to me rn - have only just started a levels but thanks for letting me know that theres another explanation haha
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ChemistryWebsite
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(Original post by charco)
No. As I explained the answer you wrote is the accepted answer.

But it is not correct.
Understood, and I'm not suggesting you're incorrect.

I humbly would say that this is a students chemistry forum, mostly high school students needing answers appropriate to their syllabus. Persuit of clarifying the very latest understanding and the model/ theories understood by academics to be closest to their observations could esily "muddy the waters" for the OP and other users.
I'm not trying to be argumentative nor to disagree with what you have said. It's perhaps not something for a forum serving mostly GCSE / A Level (and their equivalents) and some undergraduates.
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charco
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(Original post by ChemistryWebsite)
Understood, and I'm not suggesting you're incorrect.

I humbly would say that this is a students chemistry forum, mostly high school students needing answers appropriate to their syllabus. Persuit of clarifying the very latest understanding and the model/ theories understood by academics to be closest to their observations could esily "muddy the waters" for the OP and other users.
I'm not trying to be argumentative nor to disagree with what you have said. It's perhaps not something for a forum serving mostly GCSE / A Level (and their equivalents) and some undergraduates.
I follow your thread, however several specifications require that knowledge of the electrostatic nature of all bonding is understood, the IB syllabus for example.

It is not a quantum leap to the explanation of ionisation energies.

Indeed successive ionisations of, say, potassium are explained using simple electrostatic theory as evidence for energy shells. The pattern produced by 1st ionisation energies across the first 36 elements can also be explained using electrostatics

E proportional to z+z-/r is not a complicated equation.

Good students should be given good explanations.
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username2889812
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(Original post by charco)
Although this IS the accepted answer, it is not correct.

The stability of any electron is a function of the electrostatic attraction from the nucleus and the electrostatic repulsion from the other electrons.

Once an ion is formed there is less repulsion as there is 1 less electronand the electrostatic attraction from the nucleus remains the same (in the case of Mg and any other element in which we are dealing with the same energy level)

The net attraction is much greater than the repulsion, so more energy is required for ionisation.
This explanation is followed in Edexcel AS level as well ...repulsion is also termed as shielding effect...
Last edited by username2889812; 10 months ago
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ChemistryWebsite
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(Original post by charco)
Good students should be given good explanations.
We are agreed on this!
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