SCIENCE: Periodic Table: Element, atomic number 88, symbol Ra?

Questions

Who was the only Swede to hold the world heavyweight boxing championship?

What Czech runner blitzed the opposition at the 1952 Olympics?

What card game derived its name from Biritch, or Russian Whist?

Who made a famous jump on his horse Red Lancer on a cliff's edge near Mount Gambier?

What sport was standardized under the Queensberry Rules?