9/17/10

Post date: Sep 17, 2010 5:53:13 PM

Bell Ringer: Why do people form connections with each other?

• • Molecules vs. network structure

    • Molecules

      • Form when atoms that are all on the right side of the periodic table bond together

      • Small units of (usually) a few atoms bonded together

      • Strong attraction between atoms in a molecule

      • Weak or no attraction to other molecules

      • Can be solids, liquids or gases

    • Network structure

      • Forms when atoms from the left and right side of the periodic table bond together

      • Huge (millions of atoms) bonded together

      • Each atom is strongly attracted to all of the atoms near it

      • Are always solids at room temperature.

  • Elements to memorize name, symbol, and location on periodic table:

    • Hydrogen

    • Helium

    • Lithium

    • Beryllium

    • Carbon

    • Nitrogen

    • Oxygen

    • Fluorine

    • Sodium

    • Magnesium

    • Aluminum

    • Sulfur

    • Chlorine

    • Iron

    • Nickel

    • Copper

  • Electrons

    • Arranged in different levels or orbitals (shells), with each level being able to hold a certain number of electrons

      • Fill orbitals from inside to outside

      • Inside orbital only holds 2 electrons, the rest (that we study in this class) hold 8

    • Valance electrons - the electrons in the outer-most level, involved in chemical bonding

      • Periodic table shows us how many valence electrons different atoms have by which column the element is in

• • • Atoms want to have their valence electron shell level filled up completely, and can do this in 2 ways

      • Take more electrons from another atom or give up electrons to another atom

        • When an atom gains electrons or gives them up, it is called an ion

      • Share electrons with another atom

      • These two methods result in 2 different types of bonds

• • Ionic bonds