Semiconductor electronics has become crucial parts for our modern daily life. In 2018, the total sale of semiconductor products was $ 450 B'. Compare this with Auto-sales in 2018 around

$ 260 B. In view of that, you should be able to observe signature of semiconductor electronics in daily life. Answer following questions for its appreciation. (i)Why can we not simply use metals or insulators for electronics? Why do we need semiconductors? (ii)Compare the bond structure of metal and semiconductor and infer why metals have highconductivity? (iii)Name three noble prizes (scientist names and respective discoveries) that contribute to modern semiconductor electronics. (iv)Name five semiconductor devices that we use in modern electronics.