Introduction To Electricity

1. Introduction To Electricity Conductors and Insulators

2. Physical Properties of Matter • Electricity is related to the physical properties of matter. • To understand electricity we must understand the structure of the atom. • What sub-atomic particle can movein this solid? - - - - - + + + + +

3. Losing Electrons • Moving electrons are the basis for electricity. • A substance may lose electrons. • The substance has more protons than electrons. • The substance gainsa POSITIVE charge - - + + - - - + + +

4. Gaining Electrons • Moving electrons are the basis for electricity. • A substance may also gain electrons. • The substance has more electrons than protons. • The substance gainsa NEGATIVE charge - - - + - - - - + + + +

5. Electrons Passing Through • Conductors • Allow electrons to freely move through the substance • Insulators • Electrons cannot move or can only move with difficulty through the substance • Note: • Both conductors and insulators can build up positive or negative charge in the right conditions.

6. Predicting Conductors & Insulators • Use your Ohmmeter to investigate some common materials and complete the table below.

7. Questions • What physical properties can be used to classify and predict conductors and insulators? • How could you explain your classification by referring to the Periodic Table and Bohr-Rutherford electron shells? • Predict if Cesium and Iodine are conductors or insulators. • Explain why electrical wires are made out of strands of copper inside an outer covering of plastic.

8. Consolidation • Conductors • Are usually made out of metals. • Have 1, 2, or 3 electrons in their outer valence shell • They freely gain or lose electrons • Insulators • Are usually made out of non-metals. • Have 5, 6, 7, or 8 electrons in their outer valence shell • They keep a tight hold on their electrons