how can i detect the central atom in a compound? i have read somewhere dat the central element is always less electronegative than the other linked atoms? is dat enuf a criterion?

Question

ookawaiioo · Answer

Not true.  Methane (CH4) for example: Hydrogen is less electronegative than Carbon, but Carbon is the central element. 

True in sense of  SO4 (Sulfate), the central element is the less electronegative one.  

Transition metals are usually the central element because they have high oxidation number and can form 6 coordinate-covalent bonds by Lewis acid/base reaction aka Accepting/Donating electrons.

jfraser · Answer

Another handy trick is the central atom in a molecule is usually the atom that there's only one of: H2O, CH4, NH3, etc etc

ookawaiioo · Answer

What about C2H2? ;)

jfraser · Answer

^see word "usually" and when in doubt, carbon is a good bet. Never mind that hydrogen can't form more than 1 bond, so it can never be in the center