Answer: Two electrons present in the outermost shell.
Explanation: Group 2 elements of the periodic table are known as Alkaline Earth Metals . The elements are Beryllium(Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium(Ba) and Radium (Ra).
The below mentioned properties of the group 2 are common in all the elements-
a) they all are shiny and silvery white metals.
b) they all have 2 electrons in its outermost shell thus mostly exist in +2 oxidation state.
c) they are less reactive than alkali metals.
d) they are relatively soft and have low density.