Question about periodic table trend.

[Astra]

So I understand that as you go right across the periodic table: electronegativity, ionization energy, electron affinity increases

and as you go up the periodic table, the same holds true.

My question is, in the following cases, how do you compare the atoms?



Does Oxygen have a higher electronegativity,ionization energy, electron affinity increases than Cl?

Se and I?

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[aldol16]

So I understand that as you go left across the periodic table: electronegativity, ionization energy, electron affinity increases

I hope you mean "right."

As to your specific question, you likely will not encounter a question on the MCAT that requires you to make that judgment. The reason is, it varies and there's no hard and set rule for atoms that are essentially equi-distant from fluorine. Very generally speaking, elements in that are in the same row as the element of comparison will have higher electronegativity than elements that are in the same column. The reason this is is because when you're going down a column, you're adding a whole new shell of electrons, which lie farther from the nucleus, whereas within a row, you're just increasing the effective nuclear charge on a set valence shell of electrons. For the specific cases you're asking about, O is more electronegative than Cl and Se and I are equivalent in terms of electronegativity.

 

[Astra]

I hope you mean "right."

As to your specific question, you likely will not encounter a question on the MCAT that requires you to make that judgment. The reason is, it varies and there's no hard and set rule for atoms that are essentially equi-distant from fluorine. Very generally speaking, elements in that are in the same row as the element of comparison will have higher electronegativity than elements that are in the same column. The reason this is is because when you're going down a column, you're adding a whole new shell of electrons, which lie farther from the nucleus, whereas within a row, you're just increasing the effective nuclear charge on a set valence shell of electrons. For the specific cases you're asking about, O is more electronegative than Cl and Se and I are equivalent in terms of electronegativity.

Yup. meant right lol

So in the case of O and Cl, O is more electronegative.

Are there other cases where this is found that is significant? ( I am currently doing oxidation states and electronegativity is important)

 

[aldol16]

Are there other cases where this is found that is significant? ( I am currently doing oxidation states and electronegativity is important)

What do you mean here? Are you assigning oxidation states to organic compounds or metallic complexes? For organics, you don't really need to know specific electronegativities, i.e. O vs. Cl (unless in the case of hypochlorite, but I doubt something that specific will appear) - just that carbon is usually the electropostive one when bound to a heteroatom. In the case of metallics, it gets more complicated, as metals can take multiple oxidation states. But a good idea there is to model the metal as a Lewis acid and the ligands as Lewis bases. If you haven't learned how to count electrons on ligands, don't worry about it and just use the overall charge on the complex to help determine oxidation state.

 

[Astra]

What do you mean here? Are you assigning oxidation states to organic compounds or metallic complexes? For organics, you don't really need to know specific electronegativities, i.e. O vs. Cl (unless in the case of hypochlorite, but I doubt something that specific will appear) - just that carbon is usually the electropostive one when bound to a heteroatom. In the case of metallics, it gets more complicated, as metals can take multiple oxidation states. But a good idea there is to model the metal as a Lewis acid and the ligands as Lewis bases. If you haven't learned how to count electrons on ligands, don't worry about it and just use the overall charge on the complex to help determine oxidation state.

In the Kaplan book, it went over the oxidation rules. For many compounds, there are exceptions to their oxidation states when bound to a more electronegative atom, so I just wanted to get my electro negativity straight.