What do electrical conductors contain in them

Understand physics 3, textbook

66 2  Workbook, pages 32–33 Electrical conductors and non-conductors 1. Which substances conduct electricity? Power cables (Fig. 66.1) conduct electricity. The inside consists of the good conductor copper. The sheath is made of the plastic PVC, a non-conductor (insulator). Insulators prevent short circuits and protect you from getting into the circuit and endangering your life if you touch the cables. The solid conductors (Fig. 66.2) E1 Test various solid materials for their ability to conduct electricity. Apply the positive terminal of a 3 V lithium button cell to the sample. Hold the short connection (-) of a light-emitting diode (LED,  Page 87) to the negative pole of the cell. You touch the sample with the long LED connection (+). The liquid conductors (Fig. 66.3) E1, E4 Build a circuit from a power supply unit (approx. 6V / 2A), a small lamp (6V / 3W) and two clean carbon rods on stands. If the two rods are immersed in a liquid, the circuit is complete. Now test different liquids for their conductivity: distilled water, salt water, sugar water, vinegar, alcohol ... 2. How are metals structured? Metal atoms can easily donate electrons from their outer shell (valence electrons). Metals therefore always consist of positively charged metal ions and electrons that can move freely between them (Fig. 66.6). This rather loose bond allows metals to be bent and melted easily. The freely moving electrons also give metals their typical shine. If, for example, the poles of a battery are placed at the ends of a piece of metal, all freely movable electrons start moving towards the positive pole at the same time. 66.1 Various cables with copper wires and insulation made of PVC Infobox: Litz cables consist of many thin copper wires and are therefore flexible! V1 66.2 The fixed current conductors The metallic part of the clamp conducts the current. Electrical conductors are all metals (especially silver and copper) and carbon in the form of graphite (e.g. pencil lead). Non-conductors (insulators) are, for example, glass, wood and plastic. M V2 66.3 The liquid current conductors The saline solution conducts the current. Liquids conduct electricity if they contain dissolved salts (e.g. table salt) or acids (e.g. vinegar). Non-conductors are, for example, spirit (alcohol) and gasoline. M metal atoms can give off external electrons. Metals conduct electricity because freely moving electrons can move easily between the positive metal ions. M 66.4 Metals also conduct in liquid form, for example mercury switches in electric pumps. 66.5 Connections are coated with nickel, for example, so that they do not corrode (“rust”). 66.6 In metals, freely moving electrons move from the minus to the plus pole. For testing purposes only - property of the publisher öbv

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