I)with the aid of an appropriate diagram, explain the various signals which are generated when a focused beam of electrons strikes the surface of a polished section. what are each of these signals used for in mineral analysis? ii explain the origin of back-scattered (be) electrons and why they are particularly useful in analysing minerals a gold ore contains native gold, pyrite and quartz. explain how you would distinguish them on an sem screen using be electrons. i) what is the difference between characteristic x-rays and background radiation (bremmstrahlung)? explain the origin of ka, kb and la x-rays