8/26/10

Post date: Aug 25, 2010 8:31:36 PM

Bell Ringer: What is an element? What is a compound?

    • Molecule - two or more atoms that are bonded together

    • Matter is classified as either an element, a compound, or a mixture

      • Elements - made of only one kind of atom

          • The types of building blocks we have

          • Clay - different colors are different elements

          • The periodic table arranges elements by the properties of their atoms

              • Number represents number of protons

              • Mass is protons and neutrons, electrons have VERY little mass

          • Examples - Copper wire made of only copper atoms, aluminum foil made of only aluminum atoms

          • Social example - all men or all women together in a room

      • Compounds - made of two or more types of atoms

          • 2 or more elements bonded together, and cannot be separated

          • Clay - multiple colors blended together

          • Examples - water is hydrogen and oxygen, table salt is sodium and chlorine, sugar is hydrogen, oxygen, and carbon

          • We use chemical formulas to represent formulas

              • Use element symbol from periodic table

              • Use numbers to note how many of each atom we have bonded together

          • Social example - two married people (different types of people, bonded together)

      • Mixtures - Elements and/or compounds are mixed together, but could be separated again

        • Clay - little balls of different colors together, but not mashed up so you could separate them out

        • Elements and compounds are pure substances, meaning their is a fixed ratio of components. Mixtures are not pure substances, meaning you could have any ratio of components in the mixture.

        • The parts of mixtures are not bonded together, and can be separated

        • Can be solid in solid, liquid in liquid, gas in gas, or combinations.

        • Social example - non-couples in a room together, or couples in a room with other couples or with single people

  • Analogy assignment (due 8/27/10)

      • Make (and write down) an analogy for element, compound, and mixture

      • Your analogy should compare the relationship between these three types of matter to relationships you're more familiar with

      • The notes labeled "Social example" are an example of an analogy for element, mixture, and compound.

      • OR come up with a mnemonic device