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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: appleseed on March 01, 2009, 12:13:58 AM

Title: by looking at the periodic table, can i judge which pair of elements forms polar
Post by: appleseed on March 01, 2009, 12:13:58 AM

by looking at the periodic table, can i judge which pair of elements forms the most  polar substances?

Will Hydrogen and Carbon form the most polar substance
or will Carbon and oxygen?

My  idea is that the most polar will be Hydrogen and carbon because they are the furthest distance apart

what do you think

Thanks

Title: Re: by looking at the periodic table, can i judge which pair of elements forms polar
Post by: abhaymv on March 01, 2009, 12:21:31 AM

I think your idea is correct because polarity is judged by electronegativity.If the difference between the electronegativities of the compounds increase, the resultant compound's polarity should also increase.Electronegativity increases from left to right across a period.

Correct me if I am wrong.

Title: Re: by looking at the periodic table, can i judge which pair of elements forms polar
Post by: Astrokel on March 01, 2009, 12:22:50 AM

Electronegativity increases from left to right along the period and down to up from each group. Excluding noble gases, the most polar element would be F then O and N. Of course molecules' polarity also depends on its overall shape.