THE CHAIRMAN - The chairman of the Federal Reserve Ben Bernanke gives a rare interview to Scott Pelley in which he discusses pressing economic issues, including the unemployment rate, the deficit and the Fed's controversial $600 billion U.S. Treasury Bill purchase. Henry Schuster is the producer.FACEBOOK - Mark Zuckerberg, the 26-yr.-old founder and CEO of mega-social media site Facebook, talks to Lesley Stahl about his life and his business, now worth an estimated $35 billion. Shachar Bar-On is the producer. THIS IS A DOUBLE-LENGTH SEGMENT.