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sunflowers
Lv 4
sunflowers asked in Science & MathematicsChemistry · 7 years ago

Electron Configuration, level 3d?

Why is level 3d in between 4s and 4p? The same for 4d, 4f and 5s? This makes no sense to me, I can not figure out the rhyme or reason.

Update:

Would this valid way to write electrons? Write it out with all the principle levels in order, then go back and switch them around based on sublevel?

Update 2:

I can't seem to start from the beginning and fill it out correctly as I go. For some reason this concept is killing me.

Update 3:

Let me write update 1 over. The way I wrote it the first time is confusing. Would the following technique be a valid way to figure out the electron configuration of an element:

Write it out according to principle energy levels first, then go back and rearrange them according to the sublevels.

I can not seem to start from the beginning and write if correctly. For some reason I can not grasp the concept of this unless I can see it on paper.

2 Answers

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  • kumorifox
    Lv 7
    7 years ago

    The levels depend on the energy of the orbitals. Lower energy fills sooner. 4s is slightly lower in energy than 3d, so 4s fills sooner.

    In general, to determine where the levels lie, use Madelung's Rule. Let s = 0, p = 1, d = 2 and f = 3. For whichever level you have, add the shell level to the number each orbital stands for. The orbitals fill in order of the lowest total, and for identical totals, for the lowest shells first.

    1s 2s 2p 3s 3p 4s 3d 4p 5s...

    1+0 2+0 2+1 3+0 3+1 4+0 3+2 4+1 5+0...

    1 2 3 3 4 4 5 5 5...

    As you see, the totals continuously increase, and the lower shell number for identical totals fill first.

  • St N
    Lv 7
    7 years ago

    If I ever knew, I have likely forgotten, but I think the position of an electron is related to the energy level while the orbit number refers to the number of electrons in each orbit. My guess is that the electrons in 3d have more energy than 4s and 4p but still have the electron configuration of orbit 3.

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