Question

Please answer the question given in attachment with explanation.

Answer 1

Heya @User

here, answer is option (c)

explanation :-

( n ) = ultimate

(n- 1 ) = penultimate

( n-2) = Anti -penutimate

The group of elements in which the differentiating electrons enter the anti-penultimate shell of atoms are called F-block elements

=max capacity of F orbitals is 14,
so given there 1-14


*sub-shells being filled up in each period

1st period = 1s
2nd period = 2s 2p
3rd period = 3s 3p
4th period = 4s 3d 4p
5th period =5s 4d 5p
6th period =6s 4f 5d 6p
7th period = 7s 5f 6d 7p

so, the option c satisfies this order

means, when n=6 .ie, 6th period-
so value of f= (n-2) =4f
value of d = (n-1) = 5d

f-block elements always end with full filled s-orbital

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@_@Mavis:)