Electronic configurations for ions

[lorka150]

are these correct? i always get confused with the rules for the end of the order:

N^3- >> [Ne]
Tl^3+ >> [Xe]4f14 3d10
Fe^3+ >> [Ar]3d5

 

[Astronuc]

This might be helpful -

http://www.webelements.com/ (when its up and running)

or

http://www.chemie.de/web-elements-I/index.html

N electron configuration [He].2s2.2p3 then add 3e and one has

1s².2s².2p⁶, which is the same as Ne

Think of the order in the periodic table C, N, O, F, Ne

You are correct on Tl³⁺ and Fe³⁺.

 

[Blueshift5]

The electronic configurations for ions are correct. The first ion, N^3-, has gained three electrons and therefore has a filled valence shell, giving it the same electronic configuration as the noble gas neon ([Ne]). The second ion, Tl^3+, has lost three electrons and therefore has a partially filled valence shell. The first electron to be removed would come from the 6s orbital, followed by one from the 6p orbital and finally one from the 5d orbital. This results in the shortened electronic configuration [Xe]4f14 3d10. The third ion, Fe^3+, also has a partially filled valence shell, but in this case, the first two electrons to be removed would come from the 4s orbital, followed by one from the 3d orbital. This results in the shortened electronic configuration [Ar]3d5. It is important to remember that when writing electronic configurations for ions, we follow the same rules as for neutral atoms, but take into account the number of electrons gained or lost by the ion.