30 . The elements classified as typically have four valence electrons, In a forward-biased silicon diode, the current is 22 mA and the potential difference across code is 0.70 V. If the diode is connected to a battery through a 450-$2 resistor, what is thros battery potential difference? 31. As the temperature rises , the of metals is reduced. in 32. Dopants increase conductivity by_ creating an electric field 26. b . decreasing the temperature c. providing electrons or holes 27. A forward-biased silicon diode is connected to a 6.0-V battery. Also in the circuit are three d. increasing resistance 220- resistors connected in series, The diode potential difference in the circuit is 0.70 v. why is the current ? base-emitter 33. A simple device made of doped semiconductor material is called a(n) c. transistor battery d. amplifier ordi al goillness , PES-mumford yd clothing-d s to n 34. When a potential difference is put across a wire, electron speeds decrease electrons drift slowly toward the positive end of the wire 28. In a(n) , the forbidden energy gap is very large. conduction of electricity ceases electron energy lessens 29. Physicists refer to an electron deficiency as a(n)_