10.The Age of Electronic Materials 181 Plane polarized Lead-glass cylinder light Polarizer Analyzer Magnetic field direction FIGURE 10.4.Schematic representation of the rotation of the plane of polarization of plane polarized light in lead glass,when applying a magnetic field(Faraday effect).In plane polarized light,the electric vector vibrates only in one direction,shown to be the paper plane in the left part of the figure.Polarizer and analyzer are identical devices which allow the light to pass in only one vibrational direction. 1.The amount of material precipitated at an electrode is pro- portional to the quantity of electricity (current multiplied by time)consumed;see Eq.(9.11). 2.The amount of material precipitated (or liberated)at an elec- trode by a unit amount of electricity is proportional to its equivalent mass;see Eq.(9.11).(The equivalent mass of a sub- stance is the atomic mass associated with a unit gain or loss of electrons.For example,during the electrolysis of a MgCl2 solution,one unit of electricity,that is,9.649 X 104 coulombs,2 or 6.02 x 1023 electrons,3 deposits 24.312/2 grams of Mg on the negative electrode and liberates 35.453 grams of chlorine gas at the positive electrode;see Appendix IV.) Furthermore,Faraday introduced the terms anode,cathode,an- ion,cation,and electrode. Not enough,Faraday also made contributions to chemistry (liq- uefaction of chlorine under pressure,isolation of benzene,etc.), and he performed "sponsored research"on stainless steel and on glass.His fundamental studies on nonconducting materials (called dielectrics)led to a specific form of recognition:The unit of capacity (that is,the ability to hold an electric charge)was eventually named one farad.(The capacitance is one farad when one coulomb of electricity changes the potential between the plates of a capacitor by one volt,see Chapter 11 and Appendix II.)Finally,the Faraday cage was named after him.(The Faraday 2Faraday constant. 3Avogadro constant.1. The amount of material precipitated at an electrode is pro￾portional to the quantity of electricity (current multiplied by time) consumed; see Eq. (9.11). 2. The amount of material precipitated (or liberated) at an elec￾trode by a unit amount of electricity is proportional to its equivalent mass; see Eq. (9.11). (The equivalent mass of a sub￾stance is the atomic mass associated with a unit gain or loss of electrons. For example, during the electrolysis of a MgCl2 solution, one unit of electricity, that is, 9.649 104 coulombs,2 or 6.02 1023 electrons,3 deposits 24.312/2 grams of Mg on the negative electrode and liberates 35.453 grams of chlorine gas at the positive electrode; see Appendix IV.) Furthermore, Faraday introduced the terms anode, cathode, an￾ion, cation, and electrode. Not enough, Faraday also made contributions to chemistry (liq￾uefaction of chlorine under pressure, isolation of benzene, etc.), and he performed “sponsored research” on stainless steel and on glass. His fundamental studies on nonconducting materials (called dielectrics) led to a specific form of recognition: The unit of capacity (that is, the ability to hold an electric charge) was eventually named one farad. (The capacitance is one farad when one coulomb of electricity changes the potential between the plates of a capacitor by one volt, see Chapter 11 and Appendix II.) Finally, the Faraday cage was named after him. (The Faraday 10 • The Age of Electronic Materials 181 FIGURE 10.4. Schematic representation of the rotation of the plane of polarization of plane polarized light in lead glass, when applying a magnetic field (Faraday effect). In plane polarized light, the electric vector vibrates only in one direction, shown to be the paper plane in the left part of the figure. Polarizer and analyzer are identical devices which allow the light to pass in only one vibrational direction. Polarizer Plane polarized light Lead-glass cylinder Magnetic field direction N S Analyzer 2Faraday constant. 3Avogadro constant