[itsme03]

for the compound S₂N₂, it says that the Lewis structure is:
      ..
 :S=N:
  ll   l
 :N- S:
       ''
but  then the upper left sulfur doesnt obey the octet rule. plus it has 24 instead of 22 valence electrons. it says that they have zero formal charge. what does that mean and how can this be correct?

i thought it was like this:

      ..
 :S- N:
  ll   l
 :N- S:
       ''
because now there are 22 valence electrons and they all obey the octet rule, but apparently the upper left sulfur would have a positive charge and the upper right nitrogen will have a negative charge. why?

please i really want to understand this

[nj_bartel]

Octet rule only applies to row 2 elements.

[itsme03]

what about the formal charges though

[Astrokel]

Formal charges is useful when use to determine the best resonance structure becomes it is possible to draw 2 lewis structure of a molecule/ion that satisfy the octet rule. In your case like nj_bartel has mentioned that sulphur is in period 3, it is able to expand its octet structure taking it more than 8 electrons due to avaibility of d orbitals. Therefore when determine the best resonance structure, you should look out for lowest possible formal charges because sulphur need not obey the octet rule anymore.

[itsme03]

thank you so much