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Why does the 4s orbital come before the 3d?
Posted: Fri Apr 27, 2018 3:33 pm
by Mario Reyes 1C
If I heard correctly in class, the 4s orbital comes before 3d only for elements with 20 electrons or less. Can somebody explain why?
Re: Why does the 4s orbital come before the 3d?
Posted: Fri Apr 27, 2018 3:44 pm
by Joanna Pham - 2D
I was confused about this too. I don't understand the exact reason why 3d comes before 4s when writing the electron configuration.
Re: Why does the 4s orbital come before the 3d?
Posted: Fri Apr 27, 2018 5:10 pm
by Jennifer Tuell 1B
3d is at a lower energy level than 4s therefore it comes before it in the electron configuration because it going from lowest to highest energy level.
Re: Why does the 4s orbital come before the 3d?
Posted: Fri Apr 27, 2018 7:31 pm
by Nandhini_2K
The 4s orbitals are lower than 3d.
Re: Why does the 4s orbital come before the 3d?
Posted: Fri Apr 27, 2018 9:46 pm
by Joanna Pham - 2D
I am curious,why exactly does 3d have a lower energy level than 4s?
Re: Why does the 4s orbital come before the 3d?
Posted: Sat Apr 28, 2018 11:23 am
by tmehrazar
the 4s orbitals have lower energy than the 3d orbitals not the other way around, some things online say that s-orbitals are more penetrating than d-orbitals so i think that may be why
Re: Why does the 4s orbital come before the 3d?
Posted: Sat Apr 28, 2018 1:51 pm
by MadelynNguyen1F
I think 4s might fill up first because of electron repulsion. I was looking online and it said that was related to the fact that 4s fills up before 3d.
Re: Why does the 4s orbital come before the 3d?
Posted: Sat Apr 28, 2018 8:50 pm
by Alejandro Salazar 1D
The electron configuration for Cr is different, by having the 3d come first before the 4s because having two electrons in the 4s makes the orbital more unstable because of electron repulsion