Misc: what is the element for the symbol K?

Questions

How did Brad Pitt, recently married to Jennifer Aniston, refer to his ex Gwyneth Paltrow in a recent magazine interview?

Hollywood golden couple Nicole Kidman and Tom Cruise have split, but what have they said is the reason?

The first of a successful series of children's books was published in 1952. What was it called?

The 1950s saw an upsurge in the popularity of science fiction writing. Which forefather of modern SF wrote his first novel in 1952, called Player Piano?

Which play has had a continuous 50-year run?