Here's why:

* Radium (Ra) is in group 2 of the periodic table, which means it has 2 valence electrons (electrons in the outermost shell).

* To achieve a stable electron configuration, radium tends to lose these two valence electrons.

* This loss of electrons results in a positively charged ion, called the radium cation (Ra²⁺).

So, while radium as a neutral element has no charge, it typically exists as a +2 ion in compounds.