1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4
However, this is too long. So for abbreviation you can write:
[Ar] 4s23d104p4
Iron has the electron configuration [Ar]3d64s2.
The -2 charge ion with the same electron configuration as krypton is the oxide ion (O2-). Krypton has the electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6. The oxide ion gains two electrons to achieve a full valence shell, resulting in an electron configuration of 1s2 2s2 2p6.
There is no element such as 12M. Assuming that you mean 12Mg, the electron configuration is 2, 8, 2.
Se and Te will have the same valence-shell electron configuration as they are both in the same group (group 16) and have 6 valence electrons. Sr and Cs will have different valence-shell electron configurations as Sr is in group 2 with 2 valence electrons and Cs is in group 1 with 1 valence electron. N and O will have different valence-shell electron configurations as N has 5 valence electrons while O has 6. H and He will have different valence-shell electron configurations as H has 1 valence electron and He has 2.
The short electron configuration for carbon is [He] 2s^2 2p^2.
The electron configuration of selenium (Se) is [Ar] 3d10 4s2 4p4. To form a 2- ion, two electrons will be removed from the outermost shell, which is the 4p subshell. Therefore, the electron configuration of Se2- is [Ar] 3d10 4s2.
The lowest atomic number ion is Se^2-. The highest atomic number ion is Sr^2+. The ones in the middle are NOT Br^- or Rb^+. However, I do not know what the correct answer for those two is.
Iron has the electron configuration [Ar]3d64s2.
The -2 charge ion with the same electron configuration as krypton is the oxide ion (O2-). Krypton has the electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6. The oxide ion gains two electrons to achieve a full valence shell, resulting in an electron configuration of 1s2 2s2 2p6.
The electron configuration of sulfur (long) is: 1s22s22p63s23p4. The electron configuration of sulfur (short) is: [He]3s23p4.
The longhand electron configuration for sulfur is 1s2.2s2.2p6.3s2.3p4.
Cobalt electron configuration is [Ar]3d7.4s2.Cobalt(2+) electron configuration is [Ar]3d7.
There is no element such as 12M. Assuming that you mean 12Mg, the electron configuration is 2, 8, 2.
The short electron configuration for carbon is [He] 2s^2 2p^2.
Se and Te will have the same valence-shell electron configuration as they are both in the same group (group 16) and have 6 valence electrons. Sr and Cs will have different valence-shell electron configurations as Sr is in group 2 with 2 valence electrons and Cs is in group 1 with 1 valence electron. N and O will have different valence-shell electron configurations as N has 5 valence electrons while O has 6. H and He will have different valence-shell electron configurations as H has 1 valence electron and He has 2.
Beryllium electron configuration is [He]2s2.
The electron configuration of curium is [Rn]5f7.6d1.7s2.