Answer: Option (C) is the correct answer.
Explanation:
Elements of group 2 are also known as alkaline earth metals. Elements of this group are beryllium, magnesium, calcium, strontium, barium and radium.
Since, all of them belong group 2 so, they have 2 valence electrons in their outer most shell.
Also, being metals all of them except radium which is radioactive in nature are metals. They are good conductors of heat and electricity, they have shiny surface and they are also malleable and ductile in nature.
Hence, we can conclude that out of the given options in the periodic table of elements, all of the elements in group 2 have in common that each element is an alkaline earth metal.
