1/11/10

Post date: Jan 08, 2010 7:27:50 PM

Bell Ringer: Why do we divide matter into smaller groups?

• • Finish wire lab on computers

  • 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