1. CH. 4: INTRODUCTION TO ATOMS SECTION 4-5: THE PERIODIC TABLE EQ: Other than metals, what are the other regions of the Periodic Table?

2. NON-METALS KEY: Most non-metals are poor conductors of electric current and heat. Solid non-metals are dull and brittle.

3. PHYSICAL AND CHEMICAL PROPERTIES PHYSICAL PROPERTIES  Opposite properties of metals  Poor conductors  Dull  Brittle  Not malleable or ductile CHEMICAL PROPERTIES  Atoms of non-metals usually gain or share electrons  When metals and non- metals react, electrons move from metals to non-metals.  Atoms share electrons and create MOLECULES.

4. NITROGEN FAMILY  Group 15  Nitrogen is 80% of Earth’s atmosphere  Nitrogen occurs in nature as N 2. This is a diatomic molecule.

5. OXYGEN FAMILY  Group 16  Contains 3 non-metals  Examples are oxygen and sulfur.  Oxygen also forms a diatomic molecule.

6. HALOGENS  Group 17  Very reactive; all but astatine are non-metals  Gains or shares one electron  Examples are Chlorine and Fluorine.

7. INERT GAS  Group 18  These tend to be UNreactive  Do not ordinarily gain, lose or share electrons.  All inert gases exist in Earth’s atmosphere.

8. HYDROGEN  Alone in the upper left corner of the Periodic Table  The simplest of elements  Have 1 proton and 1 electron. Isotopes will have neutrons.  Most Hydrogen is combined with Oxygen to produce water.  Not classified in a family!!

9. SEMIMETALS  Properties of both metals and non-metals.  Most common elements: Silicon and Boron.  They are useful since some are semiconductors: elements that conduct electricity under certain conditions.

10. SECTION 5: RADIOACTIVE ELEMENTS  Some isotopes are unstable; their nuclei do not hold together well.  An example is Uranium.  See page 160 for Radioactive Decay  Radioactive isotopes are used in science and industry.  They are also used in medicine.