University:
York University
Course:
SC/CHEM 2020 | Introductory Organic Chemistry I
Academic year:

2022
Views:

455

Pages:

2
Author:

Niklas

Electronegativity, Polar Covalent Bonds, and Bond Dipoles Covalent bonds are characterized by the sharing of electrons between two atomic nuclei. If the atoms are identical, the electrons are shared equally, forming a nonpolar covalent bond. If the atoms are identical, then one nucleus will attract electrons more strongly than the other, forming a polar covalent bond. The ability to attract electrons in a covalent bond is governed by the element's electronegativity In a covalent bond, electrons are likely to be found near the nucleus of the more electronegative atom. This creates a separation of partial positive and negative charges along the bond, called a bond dipole. An electrostatic potential map shows a molecule's electron cloud in colors that indicate its relative charge When elements in a compound have large enough differences in electronegativity, ionic bonding can occur. Formal Charge One way to use the rules for formal charge to assign electrons: Assign electrons to atoms Compute formal charge by comparing the number of electrons assigned to the atom to the atom's group number Resonance Theory Some species are not described well by Lewis Structures because Lewis Structures imply that electrons are localized, or confined to a specific region in space. In reality, electrons are spread out, or delocalized in some molecules. • Resonance structures differ only in the placement of their valence electrons, not their atoms