1. They were both discovered by Marie and Pierre Curie.
2. They can both poison you.
3. Radium is named after the Latin word for "Ray"
4. Polonium is named after Poland, the country in which Marie Curie was born.
5. Marie and Pierre Curie obtained radium and polonium from pitchblende, a material containing uranium.
6. Polonium was discovered in 1898.
7. Radium was discovered in 1898 as well.
8. Radium and polonium are both elements on the periodic table.
9. Polonium is also called "radium F".
10. Both radium and polonium must be handled very carefully with good equipment, or their toxic fumes could spread and possibly be fatal.
Hope this helped! :)