Electron configurations of ions, Magnetic properties
1. Read chapter 7 (313-318)
2. OWLs due Thursday
Oct 26
It worked!
Z* (Z effective) is an important predictor for periodic trends as you move from left to right across a period. Think about the different reactitivities of Na and Cl – one has a small Z*, and wants to give away an electron; the other has a large Z*, and wants to gain another electron.
@ Jay Gilbert
Z* is the effective nuclear charge
The trend across a period corresponds to the increase in effective nuclear charge, therefore moving across the periodic table means increasing in atomic number and as Z* increase (Effective nuclear charge increases), the energy required to remove the electron increases.
In other words, if there is one electron in a fully positive charged atom that one electron experiences the full charge
As of, if there were many electrons, each electron shares the positive charge
Hope this helps,
Connie Diep
@Deirdre
Cr is an exception to the Aufbau rule. The electron conf is 1s2 2s2 2p6 3s2 3p6 3d5 4s1
I’m doing the OWL homework for Thursday night, and I can’t seem to get past the question that asks for the spdf notation of Cr. Isn’t it 1s2 2s2 2p6 3s2 3p6 4s2 3d4?
adam-
prof knapp told us that for the exam there were the strong bases and the strong acids we needed to know, and those are all strong electrolytes, and assume everything else was a weak acid/base, and hence weak electrolyte. that’s what I went by anyways.
Here’s a question for everyone. On the first exam there was a question that asked if “Some molecular compounds, such as acetic acid, are weak electrolytes†is a true statement. I answered that this statement was false because my understanding of electrolytes was that most molecular compounds are weak electrolytes or non-electrolytes rather than just some molecular compounds being weak electrolytes. Am I right?
Eva-
usually the lecture slides are posted by the next day.
I’m waiting too 🙂
I still can’t find the lecture slides from today…I don’t think they’re up yet. How long does it take for them to be posted usually?
has anyone else had trouble with chemical equations on owl? such as C_2_H_6_O as opposed to C_2_H_5_OH. its the same molecule but Owl doesn’t recognize it.
The lecture slides are on the right hand side under lecture. it can take a little for the to be posted.
Where can I find the recording and slides from today’s lecture?
We dont get extra credit for the optional OWLS they are there for practice.
Can someone clearify what exactly Z* is. I’m a little confused about why as you move across the periodic table there is a stronger charge felt by the electron towards the nucleus.
Do we get any extra credit (or could we get extra credit?) for doing the optional OWLs or are they just for us to practice?
Thank you yes now i understand
I concur
Jennyfer,
Fluorine has seven valence (outermost level) electrons and nine electrons overall. The 1s electrons are indeed there, but for the most part (if not all the time) they have no part in chemical reactions. And on an aside, this provides a crude reason as to why halogens are so electronegative. The fact that they have 7 out of the 8 electrons needed to form a noble gas structure explains as to why the Z* is high.
I hope this helps.
I am confused on the book it says that fluorine has 7 electrons when really shows that it has 9 electrons. why are the electrons in 1s not counted?