Question

If there are 3 electrons on every orbital, no of elements in 3rd period

Answer 1

In the forth period of periodic table there is filling of  4s orbital, 3d orbital and  4p orbital.
So the total number of orbital to be filled = 1(4s) + 5 (3d) + 3 (4p) = 9.
If each orbital can hold maximum 3 electrons then number of elements = 3 x 9 = 27


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