Polar Covalent Bonds: Carbon vs. Phosphorous

[dacruick]

I had a question in a lab about which elements are least likely to form polar covalent bonds with hydrogen. From what I understand, what governs how polar a bond is, is the electronegativity of the element. The answer said that Carbon was the one which was least likely to form the bond, but using my periodic table I see that phosphorous has the same electronegativity as hydrogen.

So shouldn't phosphorous share the bond most evenly? I've asked a couple other people and they say that phosphorous might be an exception because it can expand its octet...but that doesn't make sense to me.

Thank you,

dacruick

 

[bobze]

Are you sure you're remembering the question and elements correctly?Would you be able to list out the question in its entirety?

 

[chemisttree]

No, it doesn't make sense. P-H is fairly non-polar.