Chem: Types of Chemical Bonds

  • all about sharing—atoms come together and “share” their electrons to create a stable structure.

  • nonpolar covalent bond: the electrons are shared equally between the atoms

    • electronegativity different of less than 0.5

  • polar covalent bond: one atom is more electronegative, which means it has a higher ability to pull electrons towards itself

    • atoms are still shared, just unequally

    • electronegativity difference of greater than 0.5

  • empirical formula: simplest, most basic ratio of atoms in a molecule

  • molecular formula: gives the actual count of each atom in the molecule

  • linear: no lone pairs, sp hybridization

  • trigonal planar: no lone pairs, sp2 hybridization

  • tetrahedral: no lone pairs, sp3 hybridization

  • trigonal bipyramidal: no lone pairs, sp3d hybridization

  • octahedral: no lone pairs, sp3d2 hybridization

  • bent: 1 lone pair with sp2 hybridization or 2 lone pairs with sp3 hybridization

  • trigonal pyramidal: 1 lone pair, sp3 hybridization

  • sawhorse: 1 lone pair, sp3d hybridization

  • t-shaped: 2 lone pairs with sp3d hybridization or 3 lone pairs with sp3d2 hybridization

  • square pyramidal: 1 lone pair, sp3d2 hybridization

  • linear: 3 lone pairs with sp3d or 4 lone pairs with sp3d2

  • square planar: 2 lone pairs, sp3d2

  • electronegative atoms have a stronger bond in bonds, for example, a C-O bond is stronger than a C-N bond

  • dipole moment: the measure of the separation of partial positive and partial negative charges within a molecule

    • occurs when there is an uneven distribution of electron density, where one part of the molecule has a partial negative charge

  • ionic bond: usually between a metal and a non-metal; the more electronegative atom takes all of the electrons, no sharing

    • tend to have high melting and boiling points

    • can conduct electricity, but only when they are dissolved in water or in a molten state

    • the higher the charge on the ions, the stronger the attraction

    • smaller ions can get close together, which results in shorter bond lengths

    • the more highly charged and small the ions, the shorter and stronger the bond

  • metallic bonds: strong electrostatic attractions holding metal atoms together, formed by a sea of shared, delocalized valence electrons surrounding a lattice of positive metal ions

    • free movement of electrons in the structure gives metals their malleability and ductility

    • excellent conductors of heat and electricity

  • dative bonds (coordinate covalent bonds): form when both electrons in the bond come from the same atom.

    • common in metal complexes, where a metal ion interacts with molecules that can donate electron pairs

      • metal complexes consist of a central metal ion and is surrounded by ligands that have electrons to share, such as lone pairs of electrons available for bonding.

        • strong field ligands: ligands that form stronger bonds with the metal, which makes the complex more stable

        • weak field ligands: create less stable complexes, which means that they are more reactive because the bonds are not as strong and break more easily

  • van der waals forces: present in all molecules

    • genuinely just the basic forces that hold molecules together

    • london dispersion forces: occur due to temporary fluctuations in the electron cloud and are present in all molecules, even nonpolar ones

    • induced dipole-dipole interactions: happen when a polar molecule induces a temportary dipole in a nonpolar molecule, creating a weak attraction between them