Why 3d before 4s

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Why 3d before 4s

Postby RobertXu_2J » Sat Oct 19, 2019 7:12 pm

Why does Dr.Lavelle want us to put 3d before 4s when we are writing the electron configurations?

Jessica Castellanos
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Re: Why 3d before 4s

Postby Jessica Castellanos » Sat Oct 19, 2019 7:14 pm

When we write electron configurations, it is in order of lowest to highest energy and it turns out that 3d is lower energy than 4s, so we put 3d before 4s to keep the pattern of lowest to highest energy going. Hope this helps!

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Re: Why 3d before 4s

Postby nickianel_4b » Sat Oct 19, 2019 8:16 pm

I think the 4s and 3d states are already really close to each other to begin with, and Dr. Lavelle said that for multi-electron atoms after atomic number 20, the 4s state is higher in energy than 3d.

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