Eu cred ca este 2. Uite cateva exemple de compusi
* radium fluoride (RaF2)
* radium chloride (RaCl2)
* radium bromide (RaBr2)
* radium iodide (RaI2)
* radium oxide (RaO)
* radium nitride (Ra3N2)
Daiana90 întreabă: