Quick "effecive nuclear charge" question

[notdeadyet]

Maybe one of you genius-types can clear this up for me. I'm reading conflicting information between texts I'm using.

What is the trend on the periodic table for effective nuclear charge? Examkrackers says that it increases going left to right and top to bottom.

Left to right is logical (more electrons in same shell, so no further electron sheilding plus more protons for attraction) but the top to bottom part is counter intuitive.

When you go down a period, you're also adding a new shell, so the electrons are further away and there is more sheilding effect. I realize you have slightly more protons, but that couldn't offset it. Is this a typo in Examkrackers?

---

Members don't see this ad.

 

[doublehh03]

Maybe one of you genius-types can clear this up for me. I'm reading conflicting information between texts I'm using.

What is the trend on the periodic table for effective nuclear charge? Examkrackers says that it increases going left to right and top to bottom.

Left to right is logical (more electrons in same shell, so no further electron sheilding plus more protons for attraction) but the top to bottom part is counter intuitive.

When you go down a period, you're also adding a new shell, so the electrons are further away and there is more sheilding effect. I realize you have slightly more protons, but that couldn't offset it. Is this a typo in Examkrackers?

i think it increases across a period (so that's right) but DECREASES down a group b/c like u said, e- are then starting to fill up the d and f orbitals

 

[Condeeleza Rice]

it increases from top to bottom but coloumbs law takes over from top to bottom. Remember F=kq1q2/r^2

 

[Polodog21]

i think it increases across a period (so that's right) but DECREASES down a group b/c like u said, e- are then starting to fill up the d and f orbitals

double is right!

 

[notdeadyet]

double is right!

Thanks, all!

 

[QofQuimica]

Thanks, all!

I wrote a post about this in the gen chem explanations thread in the MCAT subforum that you may want to talke a look at.

 

[notdeadyet]

Thanks, Q. Are we not in the MCAT subforum? Do you have a thread title, by any chance?

 

[QofQuimica]

Thanks, Q. Are we not in the MCAT subforum? Do you have a thread title, by any chance?

No, this is the main MCAT forum. If you look at the top of the MCAT forum page, you will see a subforum called "Study Questions Q & A." That is the MCAT subforum. I have set up question threads in there for each MCAT subject, as well as explanations threads for each subject. These do exactly what you'd expect them to do. The question threads are for studiers to ask us questions, and the explanations threads are explanations of various topics in each MCAT subject. Here is the link to the General Chemistry Explanations Thread. Hope you find it helpful.