Radium is a member of the alkaline earth family. In addition to being a part of this family, what is another property of radium that you can deduce from the information given in the periodic table?

Responses
A The atomic number tells us that radium is a synthetic element.The atomic number tells us that radium is a synthetic element.
B Based on its location overall, radium is considered a nonmetal.Based on its location overall, radium is considered a nonmetal.
C The atomic mass and atomic number tell us that radium is a radioactive element.The atomic mass and atomic number tell us that radium is a radioactive element.
D The period number tells us that radium is the least reactive member of the family.

C The atomic mass and atomic number tell us that radium is a radioactive element.