Question

why (k)potassium 19th electron enter 3d orbitals 4s orbital
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Answer 1

Answer:

Following Hunds Rule?

Explanation:

Answer 2

Answer:

Atomic no. Of potassium is 19

Then filling its orbitals according to the rules

1s2 2s2 2p6 3s2 3p6 upto here it achieves stable argon gas configuration then the last electron that remains unpaired goes into 4s orbital but since its unpaired it is unstable and tries to lose and electron to achieve stability

Explanation:

As the rule states 4s orbital is filled before 3d orbital