Answer:
The notation of configuration of Co is [tex][Ar] 3d^7 4s^2[/tex]
(A) is correct option.
Explanation:
Given that,
The following notations is the correct noble gas configuration for Co.
(A). [Ar] 3d⁷ 4s²
(B). [Ar] 4s² 4p⁶ 3d
(C). [Kr] 4s² 4p⁶ 4d
(D). [Co] 3d⁷ 4s²
We know that,
Cobalt :
Co is the symbol of cobalt which is a chemical element.
Atomic number of Co is 27.
We need to find the notation of the configuration of noble gas Co
Using configuration
[tex]Co_{27}=2, 8, 15, 2[/tex]
[tex]Co_{27}=1s^2, 2s^2,2p^6, 3s^2 3p^6 3d^7, 4s^2[/tex]
So, we can write as the notation of noble gas configuration
[tex]Co_{27}=[Ar] 3d^7 4s^2[/tex]
Hence, The notation of configuration of Co is [tex][Ar] 3d^7 4s^2[/tex]
(A) is correct option.