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Covalent Bond Polarity

 

Bend--> Bonds Electronegativity Differences

Step 1- Is the bond Ionic or Covalent?

quick way--> metal (left side of the periodic table) to nonmetal (right side) = IONIC

Nonmetal to nonmetal (both on the right side of the periodic table, H is a nonmetal)=Covalent

 

(Other way--> subtract the electronegativities. If >1.7 it is IONIC, <1.7 is covalent. Exceptions HF, BF3, BF2 )

 

Step 2- What type of covalent bond do you have?

So you know it is covalent. MY RULE

If it is 2 of the same element bonded it is a NONPOLAR bond. If they are different it is a POLAR bond. (works 99% of the time).

-C=C- H-H O=O -C=O H-Cl
nonpolar nonpolar nonpolar polar polar

***If and when you have to explain bond polarity, just state "there is a difference in electronegativities", or "there is no difference in electronegativities".

Same element, same electronegativities=no difference.

Different element, different electronegativity=difference.

Bend--> Bonds Electronegativity Differences

The other way

To determine the polarity of a covalent bond using numerical means, the difference between the electronegativity of the atoms is taken. If the result is between 0.4 and 1.7 then, generally, the bond is polar covalent.

So what does a Polar Covalent bond actually represent?

Since there is a difference in electronegativities, one of the atom unequally shares the electrons (it hogs it), and thus becomes ever so slightly negative. The other atom becomes slightly positive. These have a partial charge (ions have full charges). We represent a partial charge with a lowercase Greek delta (d).

The arrow beneath the bond indicates the positive and points to the negative side.

On to Molecules Polarity

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