ChEM: ground state eltron configuration

[NickP717]

Homework Statement

Al3+
N3-
Li+
Au+
Sr2+
Mn2+
Tl+
Br -

Homework Equations

The Attempt at a Solution

no clue, the positives and negatives are messing me up

 

[hage567]

Do you understand what the positives and negatives mean?

 

[Blueshift5]

The ground state electron configuration for each of these ions can be determined by using the periodic table and the rules for filling orbitals.

Al3+: [Ne]3s^2 3p^1
N3-: [He]2s^2 2p^6
Li+: [He]2s^1
Au+: [Xe]4f^14 5d^9 6s^1
Sr2+: [Kr]5s^2
Mn2+: [Ar]3d^5
Tl+: [Xe]4f^14 5d^10 6s^2 6p^0
Br-: [Ar]3d^10 4s^2 4p^6

Each ion has a different number of electrons and therefore a different electron configuration. The symbol in brackets represents the noble gas configuration, meaning the number of electrons in the outermost energy level is the same as the noble gas element. For example, Al3+ has the same electron configuration as neon (Ne) with 10 electrons in the outermost energy level.

It is important to note that when an ion has a positive charge, it has lost electrons and therefore its electron configuration will have fewer electrons than the neutral atom. When an ion has a negative charge, it has gained electrons and its electron configuration will have more electrons than the neutral atom.

I hope this helps clarify the concept of ground state electron configurations for these ions. If you have any further questions, please feel free to ask.