Bioreview - A polar covalent bond is In a polar covalent bond the electrons shared by the atoms spend a greater amount of time on the average

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A polar covalent bond is…? In a polar covalent bond, the electrons shared by the atoms spend a greater amount of time, on the average, closer to the Oxygen nucleus than the Hydrogen nucleus. This is because of the geometry of the molecule and the great electronegativity difference between the Hydrogen atom and the Oxygen atom. Peptide bonds/amines/water are all polar covalent bonds What determines whether a bond is polar/non-polar/covalent/ionic? Covalent bonds are formed as a result of the sharing of one or more pairs of bonding electrons. Each atom donates half of the electrons to be shared. The polarity of a bond and whether or not it is ionic is determined by the electronegativity of the two atoms involved in the bond. Electrons are not always shared equally between two bonding atoms: one atom might exert more of a force on the electron cloud than the other. This "pull" is termed electronegativity and measures the attraction for electrons a particular atom has. If the electronegativities of the two atoms in the bond are exactly equal or very close to equal, then the bond is non-polar covalent . This is always the case if the two atoms bonded are identical to each other, but sometimes two atoms have very similar electronegativities to each other, resulting in a non-polar bond. If the electronegativities are very different, then the bond is ionic (if the difference is greater than 1.7). If the electronegativities are similar, but not equal, then the bond is polar covalent (if the difference is greater than 0.5 but less than 1.7) As the difference in electronegativity increases the bond gets more and more polar until it is considered ionic . How can you determine the electronegativity of an element? What is the difference between ionic (completely polar) and covalent ? Only bonds are called "covalent," but "ionic" can refer to both bonds and compounds. A compound that has covalent bonds in it is called "molecular," and a compound that has ionic bonds in it is called "ionic." Bonds vs. Compounds In chemical bonds , atoms can either transfer or share their valence electrons. In the extreme case where one or more atoms lose electrons and other atoms gain
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This note was uploaded on 04/12/2008 for the course BIO 311D taught by Professor Reichler during the Spring '08 term at University of Texas at Austin.

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Bioreview - A polar covalent bond is In a polar covalent bond the electrons shared by the atoms spend a greater amount of time on the average

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