carbon [C] barium [Ba] sodium [Na] manganese [Mn]
I gave my students this multiple choice question: Based on the Periodic Table of the Elements, which of these elements has properties most similar to calcium (Ca)?

Only one answer is correct among these 4 choices:
- carbon [C]
- barium [Ba]
- sodium [Na]
- manganese [Mn]

Could you tell me which one is correct?

barium [Ba]