Unformatted text preview: electrons spend surrounding each atom's nucleus. If an atom is highly electronegative, it strongly attracts electrons. In a covalent bond, this means all of the electrons (in the outer shell) spend more time around the more electronegative atom. If you subtract the electronegativity values of two atoms and the result is large, it's a polar molecule. If the difference in electronegativity is small, it's non-polar . In biology, the really important atoms/elements are : Hydrogen, Oxygen, Carbon, Nitrogen These are found in all organisms and the key biological molecules (carbohydrates, proteins, nucleic acids and lipids) each contain at least three of them. Therefore, in terms of biology, the highly polar covalent bonds involve some of these 4 atoms. So, which bond is the most polar in biology? (You don't need to know the numbers.) How do you know? Why is the C-H bond (very common in biological molecules) considered non-polar?...
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- Spring '08
- Biology, electronegative atom