Question

Total no. of electron of 5th period which have one or more than one 5d electron
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Answer 1

➡Since s = ± 1 / 2 , each orbital can fit two electrons, thus total count of electrons is = 2 × 9 = 18 , which is also the total number of elements in the third shell. In your question, the only change is that each orbital can now hold three electrons (by some phenomenon we don't know yet!)