[narutodemonkill]

CH3SCN how would you draw something like this. I got the correct structure in which sulfur has two lone pairs and nitrogen forms a triple bond with carbon.

But how do you know which one is the central atom it is suppose to be the most E.N and also the one which you distribute the electrons to last.

[Schrödinger]

Why do you think the most electronegative atom has to be the central atom? Is that something like a convention that I am ignorant of?

[narutodemonkill]

Why do you think the most electronegative atom has to be the central atom? Is that something like a convention that I am ignorant of?

thats was a general rule we were told in class,

[Schrödinger]

But what about cases like H₂SO₄, H₃PO₄, NO₂, SO₂, SO₃, CO₂, etc..

There are a lot more examples where the 'central atom' is actually the less electronegative one. So, I think we just call an atom 'central atom' because it's easy to analyze the structure of a molecule using it like a reference point/origin.

Please forgive me if what I'm saying is wrong/makes no sense... This is just my personal opinion

[lnhquang]

I don't think that the most electronegative atom is supposed to be the central atom. According to what I know, one of the rules for writing Lewis structure is that we usually put the smaller electronegative atom in the center, except that hydrogen is always at frontier position.