Question

the number of electrons present in the 4f-subshell gadolinium(z=64)

Answer 1

Answer:

The electronic configuration of La(Z=57) is [Xe]5d

1

6s

2

. Therefore, further addition of electrons occurs in a lower energy 4f-orbital till it is exactly half filled at Eu(Z=63). Thus,the electronic configuration of Eu is [Xe]4f

7

6s

2

. Therefore, addition of next electron doesn't occur in a more stable exactly half-filled 4f

7

shell but occur in a little higher energy 5d-orbital. Thus, the electronic configuration of Gd(Z=64) is [Xe]4f

7

5d

1

6s

2

.

Explanation:

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Answer 2

Answer:

Explanation:

Gadolinium

Z=64

symbol:Gd

block : F block

period: 6 period

Electronic configuration

expected: [Xe]4f 8 6s 2

observed:[Xe]4f7 5d1 6s2

Reason: Half filled f orbital is more stable than partially filled f orbital and since energy difference is not much between 4f orbital and 5d orbital thus 1 electron from 4f orbital(expected to have 8e) jumps to 5d orbital making it 5d1 thus deviating from the expected configuration and conferring stability through hund’s rule of maximum multiplicity.