On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.

Asked by Pragya Singh | 1 year ago |  91

1 Answer

Solution :-

In a periodic table containing elements, a period shows the value of a principal quantum number (n) for the furthest shells. Every period starts with the filling with the principal quantum number (n). And n’s value for the 6th period is equal to 6. Now, for n = 6, the azimuthal quantum number (l) can have “0, 1, 2, 3, 4” values.

As indicated by Aufbau’s rule, electrons will be added to various orbitals according to their increasing energies. Here, the 6d subshell is having much higher energy than the energy of 7s subshell.

In the sixth period, the electrons can occupy in just 6s, 4f, 5d, and 6p subshells. 6s is having 1 orbital, 4f is having 7 orbitals, 5d is having 5 orbitals, and 6p is having 3 orbitals. In this way, there are a sum of 16 (1 + 7 + 5 + 3 = 16) orbitals accessible. As indicated by Pauli’s exclusion, one orbital can only accommodate at max 2 electrons. Hence, sixteen orbitals can have 32 electrons. Subsequently, the 6th period of the period table ought to have 32 elements.

Answered by Pragya Singh | 1 year ago

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