The aufbau principle is a method for determining the electron configuration of an element. It shows how the various orbitals must be filled in correct sequence to show how ionization may occur. For selenium, the correct aufbau sequence is [AR] 4s2 3d10 4p4.
It is [Ar] 3d10 4s2 4p4
Sulfurs noble gas core electronic configuration is [Ne]3s2 3p4
Selenium: [Ar]3d104s24p4 Phosphorus: [Ne]3s23p3
It is [Ar] 3d10 4s2 4p4
Selenium should gain two electrons and lose six electrons to achieve a noble gas electron configuration.
The noble gas configuration for Sr (strontium) is [Kr]5s2
Sulfurs noble gas core electronic configuration is [Ne]3s2 3p4
Selenium: [Ar]3d104s24p4 Phosphorus: [Ne]3s23p3
Selenium should gain two electrons and lose six electrons to achieve a noble gas electron configuration.
It is [Ar] 3d10 4s2 4p4
The noble gas configuration for Sr (strontium) is [Kr]5s2
[He] 2s1
Co is cobalt and is not a noble gas. Cobalt is a transition metal. Its electron configuration is [Ar]3d74s2.
The electron configuration and noble gas core for Li+ is that of He: Li+: (1s2, 2s0)
[Ar]3d74s2
The noble gas configuration for Sr (strontium) is [Kr]5s2
The electron configuration for a ground-state potassium atom is 1s22s22p63s23p64s1. The noble gas shorthand configuration is [Ar]4s1.
The noble configuration for Ca is [Ar]4s2.