How is the Lewis structure of an ion written?

Question

Skylar Alexander · Accepted Answer

The same way you draw the structure of the original molecule or atom, except with #X# more or #X# less electrons, depending on the charge.

i.e. if charge is #-2#, then add #2# electrons (because the charge of an electron is #-1.602xx10^(-19) C# and is thus the same sign as the charge), and vice versa for charges of #pmX#.

So if you use the "counting valence electrons" method, you can draw #SO_4^(2-)# by saying that:

#S: 6#
#O_4: 6*4 = 24#
#"From 2- charge: " 2#

Total: #6+24+2 = color(green)(32)#

Count the electrons in here:
:

"Owned" electrons:

#6# per thionyl oxygen (#S=O#), so #12# total.
#7# per oxygen with a formal charge of #-1# (from #6 - 7#), so #14# total.
#6# per sulfur, so #6# total.
Sure enough, it matches:
#12+14+6 = color(green)(32)#

Sarah Angotti · Answer

undefined Write the Lewis structure of an ion by adjusting the number of valence electrons based on the ion's charge. Add or remove electrons accordingly, then depict the structure using the appropriate symbols and lines.

Delilah Anderson · Answer

undefined The Lewis structure of an ion is written by considering the total number of valence electrons in the ion and adjusting the number of electrons to account for the ion's charge. Once the total number of valence electrons is determined, electrons are placed around the atoms to satisfy the octet rule (or duet rule for hydrogen and helium) for each atom in the ion. Lone pairs and bonding pairs of electrons are arranged to minimize formal charges on the atoms. Additionally, brackets and the charge of the ion are included to denote the overall charge of the ion.