9/22/10

Post date: Sep 21, 2010 7:40:29 PM

Bell Ringer: Compare and contrast ionic and covalent bonds

    • Atoms don't always share equally

      • When two different elements bond together, sometimes the electrons are more attracted to one nucleus than the other. This is called a polar covalent bond. (when electrons are equally attracted to each nucleus, we call it a nonpolar covalent bond)

      • Electrons are typically more attracted to elements that are farther to the right and higher up on the periodic table of elements.

  • Ionic and Covalent Bonding

    • Go over homework

      • I2

      • S2

      • H20

      • NH3

      • P2

  • Work on bonding practice worksheet (due tomorrow if not finished in class)

    • Metallic Bonds

      • Cross between ionic and covalent compounds

      • Atoms group together, similar shape to a network

      • Outer layers of electrons overlap, and are shared with neighbors

        • Electrons are shared between ALL atoms, and can flow freely

      • Metals conduct electricity and are flexible because their atoms and electrons can move freely throughout the metal's structure

    • Polyatomic Ions

      • Breaking down the word:

        • Poly = many

        • Atomic = made of atoms

        • Ion = body that has a non-zero charge

      • Molecules with a charge

      • Stick together as a group (behave like a single unit), can bond with other ions

      • Many common examples

        • NaHCO3 = baking soda

        • Na2CO3 = used to make soaps and cleaners

      • Oppositely charged polyatomic ions can bond together to make larger compounds

        • (NH4)2SO4

      • Use parentheses to separate a polyatomic ion from the rest