An atom of radium (Ra) forms a monatomic ion. Which ion does it most likely form?
a- Ra2-
b- Ra-
c- Ra2+
d- Ra+

The atomic number of the element Radium (Ra) is 88. It is an alkaline earth metal. Electronic configuration of Radium (Ra) will be [Rn]7s^{2}[Rn]7s

2

It belongs to the group IIA of the periodic table. Alkaline earth metals that belong to the group IIA of the periodic table lose the valence electrons to form a +2 ion.

Therefore, Radium with an electronic configuration of [Rn]7s^{2}[Rn]7s

2

will lose the two 7s electrons to form the cation with +2 charge.