Energy band model a) For silicon, if Eg decreases by 0.078 eV, by what fraction does ni increase (assume T is constant at 300K)? b) If the temperature rises from 300K to 600K, by what additional fraction does n, increase (assume Eg is constant 1.068 eV, you do not need to worry about the decrease from problem a)? c) If we further increase the temperature, Si starts exhibiting semi-metal properties. Think ofa physical reason for this phenomenon.