How many valence electrons dose Ra have?

1 Answer
Jun 23, 2017

Answer:

Radium, Ra, has two valence electrons.

Explanation:

Radium is in group 2/IIA, and all of the elements in that group have two valence electrons. You can also determine the number of valence electrons from its electron configuration, which is #"[Rn]7s"^2"#. For the representative elements, groups 1/IA, 2/IIA, and groups 13/IIIA-18/VIIIA, valence electrons are the electrons in the #"s"# and #"p"# sublevels in the highest energy level, in this case #7#.