Calculating electronegativity differences

[Akitirija]

Hi, everyone!

Just a quick question to be sure:

I want to calculate the electronegativity difference of $Na_{2}O,\ \Delta X_{Na_{2}O}$,

Is this correct:

$\Delta X_{Na_{2}O}=X_{O}-X_{Na}$

Or is it:

$\Delta X_{Na_{2}O}=X_{O}-2*X_{Na}$ (since there are 2 Na atoms).

 

[DrDu]

The first alternative without the factor 2 is correct. Usually, you use the electronegativity difference to estimate the polarity of a bond between two atoms. Other atoms bonded to these atoms are not relevant.

 

[Akitirija]

Thank you very much for your quick reply, DrDu!